Robust DEA efficiency scores: A probabilistic/combinatorial approach

In this paper we propose robust efficiency scores for the scenario in which the specification of the inputs/outputs to be included in the DEA model is modelled with a probability distribution. This proba- bilistic approach allows us to obtain three different robust efficiency scores: the Conditional Expected Score, the Unconditional Expected Score and the Expected score under the assumption of Maximum Entropy principle. The calculation of the three efficiency scores involves the resolution of an exponential number of linear problems. The algorithm presented in this paper allows to solve over 200 millions of linear problems in an affordable time when considering up 20 inputs/outputs and 200 DMUs. The approach proposed is illustrated with an application to the assessment of professional tennis players

Making information accessible

A description is given of a new approach to provide information to cassava workers and the creation of a Cassava Information Center, one of a worldwide network of centers providing highly specialized, current information to agricultural researchers. Factors are described that have contributed to the success of this type of centre and their orientation towards the solution of food- production deficits in the world by using a commodity-oriented strategy. The following are analyzed: the relation between information and research; characteristics of the Latin American scientist regarding information production and consumption; publication infrastructure, that in Latin America is another illustration of the vicious circle of under-development; the services offered by the Scientific Information Exchange Unit at the Centro Internacional de Agricultura Tropical (CIAT); and the concept of consolidated information that includes not only the recollection and dissemination of the results of research but also the mechanisms that synthesize these results and integrate them as scientific and technical knowledge to contribute to the advance ofscience and to the solution of problems. (CIAT

Advanced Oxidation of Drinking Water using Ultraviolet Light and Alternative Solid Forms of Hydrogen Peroxide

With the increasing focus on removing emerging, unregulated drinking water contaminants, the use of advanced oxidation processes (AOPs) has become more prevalent. A commonly used AOP is the ultraviolet light/hydrogen peroxide (UV/H2O2) AOP. This process utilizes the formation of hydroxyl radicals to oxidize contaminants to less harmful forms. In this analysis, two alternative solid forms of H2O2, sodium perborate (SPB) and sodium percarbonate (SPC) were used as sources of H2O2 in the UV/H2O2 AOP. The potential advantage of SPB and SPC is that they are solids in nature, and as a result, the shipping costs and shipping energy requirements can be reduced significantly compared to that of liquid H2O2. The yields of active H2O2 via SPB and SPC were investigated in deionized (DI) water and three natural water sources from the Northampton, MA Water Filtration Plant. In DI water, the active yields of H2O2 via SPB and SPC were much higher than in the vii natural water sources. The findings of this analysis indicate that both SPB and SPC are viable sources of H2O2, especially in waters that are treated to reduce the background carbonate concentration. In highly finished waters similar to DI water, it is expected that the use of SPB and SPC will result in reduced oxidation rates of drinking water contaminants. Therefore, the use of SPB and SPC as H2O2 sources in the UV/H2O2 AOP in highly finished waters is not encouraged. In natural water sources, SPB and SPC appear to be viable alternatives to liquid H2O2 for use in the UV/H2O2 AOP up to active H2O2 concentrations of 5mg/L. Using SPB and SPC has the potential for significant cost savings depending on the source of the water used in the drinking water treatment process. For facilities with surface waters as the source water, significant cost savings are possible. However water reclamation and reuse facilities have high purity source waters and SPB and SPC as sources of H2O2 are more costly alternatives. The reduction in treatment facilities carbon footprints‟ associated with shipping H2O2 is largely dependent on the location of the chemical production facilities of each reagent

Chemical Segregation in Hot Cores With Disk Candidates: An investigation with ALMA

In the study of high-mass star formation, hot cores are empirically defined stages where chemically rich emission is detected toward a massive YSO. It is unknown whether the physical origin of this emission is a disk, inner envelope, or outflow cavity wall and whether the hot core stage is common to all massive stars. We investigate the chemical make up of several hot molecular cores to determine physical and chemical structure. We use high spectral and spatial resolution Cycle 0 ALMA observations to determine how this stage fits into the formation sequence of a high mass star. We observed the G35.20-0.74N and G35.03+0.35 hot cores at 350 GHz. We analyzed spectra and maps from four continuum peaks (A, B1, B2 and B3) in G35.20, separated by 1000-2000 AU, and one continuum peak in G35.03. We made all possible line identifications across 8 GHz of spectral windows of molecular emission lines and determined column densities and temperatures for as many as 35 species assuming local thermodynamic equilibrium. In comparing the spectra of the four peaks, we find each has a distinct chemical composition expressed in over 400 different transitions. In G35.20, B1 and B2 contain oxygen- and sulfur-bearing organic and inorganic species but few nitrogen-bearing species whereas A and B3 are strong sources of O, S, and N-bearing species (especially those with the CN-bond). CH$_2$DCN is clearly detected in A and B3 with D/H ratios of 8 and 13$\%$, respectively, but is much weaker at B1 and undetected at B2. No deuterated species are detected in G35.03, but similar molecular abundances to G35.20 were found in other species. We also find co-spatial emission of HNCO and NH$_2$CHO in both sources indicating a strong chemical link between the two species. The chemical segregation between N-bearing organic species and others in G35.20 suggests the presence of multiple protostars, surrounded by a disk or torus.Comment: 14 pages with 13 figures main text, 54 pages appendi

On capacity expansion planning under strategic and operational uncertainties based on stochastic dominance risk averse management

A new scheme for dealing with uncertainty in scenario trees is presented for dynamic mixed 0–1 optimization problems with strategic and operational stochastic parameters. Let us generically name this type of problems as capacity expansion planning (CEP) in a given system, e.g., supply chain, production, rapid transit network, energy generation and transmission network, etc. The strategic scenario tree is usually a multistage one, and the replicas of the strategic nodes root structures in the form of either a special scenario graph or a two-stage scenario tree, depending on the type of operational activity in the system. Those operational scenario structures impact in the constraints of the model and, thus, in the decomposition methodology for solving usually large-scale problems. This work presents the modeling framework for some of the risk neutral and risk averse measures to consider for CEP problem solving. Two types of risk averse measures are considered. The first one is a time-inconsistent mixture of the chance-constrained and second-order stochastic dominance (SSD) functionals of the value of a given set of functions up to the strategic nodes in selected stages along the time horizon, The second type is a strategic node-based time-consistent SSD functional for the set of operational scenarios in the strategic nodes at selected stages. A specialization of the nested stochastic decomposition methodology for that problem solving is outlined. Its advantages and drawbacks as well as the framework for some schemes to, at least, partially avoid those drawbacks are also presentedThis research has been partially supported by the projects: MTM2015-63710 and MTM2016-79765 from the Spanish Ministry of Economy and Competitiveness. The authors like to thank the positive criticism of their colleagues Antonio Alonso-Ayuso, Luis Cadarso, F. Javier Martín-Campo and Angel Marín that helped to improve the presentation of the wor

Resistance to eyespot (Pseudocercosporella herpotricoides) and distribution of biochemical markers in hexaploid lines derived from double cross (Triticum turgidum x Aegilops ventricosa) x T. aestivum

There are not good intraspecific sources of resistance to the eyespot disea se of wheat, aaused by Cercosporella herpotrichoides Fvon . The -ínterspecifia transfer of genes for resistanoe from Aegitops ventricosa into hexaploid wheat has been only partially achieved, because the degree of resistanoe attained is not as high as that of the donor. We report here on the transfer of resistanoe in a double oross (Triticum turgidum var. rubroatrwv H-1-1 x Ae.ventricosa AP-D x T.aestivum cv. Almatense H-10-15. The high level of resistanoe in a high proportion of the lines strongly suggests a simple genetic control for this oharacter (possibly by one major gene). The gene(s) responsible for resistanoe in the selected lines must be associa ted with the D genome of Aegilops ventricosa on the basis of a detailed study of the distribution of biochemioal markers in the H-93 lines. These results do not exelude that genes with similar effeets might be looated in the M° genome

On the time-consistent stochastic dominance risk averse measure for tactical supply chain planning under uncertainty

In this work a modeling framework and a solution approach have been presented for a multi-period stochastic mixed 0–1 problem arising in tactical supply chain planning (TSCP). A multistage scenario tree based scheme is used to represent the parameters’ uncertainty and develop the related Deterministic Equivalent Model. A cost risk reduction is performed by using a new time-consistent risk averse measure. Given the dimensions of this problem in real-life applications, a decomposition approach is proposed. It is based on stochastic dynamic programming (SDP). The computational experience is twofold, a compar- ison is performed between the plain use of a current state-of-the-art mixed integer optimization solver and the proposed SDP decomposition approach considering the risk neutral version of the model as the subject for the benchmarking. The add-value of the new risk averse strategy is confirmed by the compu- tational results that are obtained using SDP for both versions of the TSCP model, namely, risk neutral and risk averse.The authors would like to thank to the two anonymous review- ers for their help on clarifying some concepts presented in the manuscript and strongly improving its presentatio