1,807 research outputs found
Entity linking on philosophical documents
No full textEntity Linking consists in automatically enriching a document by detecting the text fragments mentioning a given entity in an external knowledge base, e.g., Wikipedia. This problem is a hot research topic due to its impact in several text-understanding related tasks. However, its application to some specfiic, restricted topic domains has not received much attention. In this work we study how we can improve entity linking performance by exploiting a domain-oriented knowledge base, obtained by filtering out from Wikipedia the entities that are not relevant for the target domain. We focus on the philosophical domain, and we experiment a combination of three different entity filtering approaches: one based on the Philosophy" category of Wikipedia, and two based on similarity metrics between philosophical documents and the textual description of the entities in the knowledge base, namely cosine similarity and Kullback-Leibler divergence. We apply traditional entity linking strategies to the domainoriented knowledge base obtained with these filtering techniques. Finally, we use the resulting enriched documents to conduct a preliminary user study with an expert in the area
Fluorinated porous organic frameworks for improved CO2 and CH4 capture
No full textA porous 3D selectively fluorinated framework (F-PAF1), robust yet flexible and with a surface area of 2050 m(2) g(-1), was synthesised by condensation of an ad hoc prepared fluorinated tetraphenylmethane (TPM) monomer to ensure homogenously distributed C-F dipoles in the swellable architecture. Tetradentate TPM was also the comonomer for the reaction with fluorinated difunctional monomers to obtain frameworks (FMFs) with a controlled amount of regularly spaced reorientable C-F dipoles. The isosteric heat of adsorption of CO2 was increased by 53% by even moderate C-F dipole insertion, with respect to the non-fluorinated frameworks. CO2/N-2 selectivity was also increased up to a value of 50 for the difluoro-containing comonomer. Moreover, methane shows optimal interaction energies of 24 kJ mol(-1)
Effect of irrigation and nitrogen fertilization on the production of biogas from maize and sorghum in a water limited environment
No full texttThe expansion of biogas production from anaerobic digestion in the Po Valley (Northern Italy) has stim-ulated the cultivation of dedicated biomass crops, and maize in particular. A mid-term experiment wascarried out from 2006 to 2010 on a silt loamy soil in Northern Italy to compare water use and energyefficiency of maize and sorghum cultivation under rain fed and well-watered treatments and at tworates of nitrogen fertilization. The present work hypothesis were: (i) biomass sorghum, for its efficientuse of water and nitrogen, could be a valuable alternative to maize for biogas production; (ii) reductionof irrigation level and (iii) application of low nitrogen fertilizer rate increase the efficiency of bioenergyproduction. Water treatments, a rain fed control (I0) and two irrigation levels (I1 and I2; only one in2006 and 2009), were compared in a split–split plot design with four replicates. Two fertilizer rates werealso tested: low (N1, 60 kg ha−1of nitrogen; 0 kg ha−1of nitrogen in 2010) and high (N2, 120 kg ha−1of nitrogen; 100 kg ha−1of nitrogen in 2010). Across treatments, sorghum produced more abovegroundbiomass than maize, respectively 21.6 Mg ha−1and 16.8 Mg ha−1(p < 0.01). In both species, biomass yieldwas lower in I0 than in I1 and I2 (p < 0.01), while I1 and I2 did differ significantly. Nitrogen level neveraffected biomass yield. Water use efficiency was generally higher in sorghum (52 kg ha−1mm−1) than inmaize (38 kg ha−1mm−1); the significant interaction between crop and irrigation revealed that water useefficiency did not differ across water levels in sorghum, whereas it significantly increased from I0 and I1to I2 in maize (p < 0.01). The potential methane production was similar in maize and sorghum, while itwas significantly lower in I0 (16505 MJ ha−1) than in I1 and I2 (21700 MJ ha−1). The only significant effectof nitrogen fertilization was found in the calculation of energy efficiency (ratio of energy output andinput) that was higher in N1 than in N2 (p < 0.01). These results support the hypothesis that (i) sorghumshould be cultivated rather than maize to increase energy efficiency, (ii) irrigation level should replace upto 36% of ETr and (iii) nitrogen fertilizer rate should be minimized to maximize the efficiency in biomassproduction for anaerobic digestion in the Po Valley
A framework to support the selection of front-end and back-end solutions in omnichannel retailing
No full textThe goal of this paper is to address the operational challenges of omnichannel (OC) retailing, a popular model that merges online and offline channels to provide a seamless service experience to consumers throughout their customer journey. Embracing OC implies (i) deciding which shopping alternatives should be offered (front-end solutions), and (ii) designing appropriate logistics processes (back-end solutions). The study presents a framework supporting the configuration of omnichannel (OC) strategies through an empirical approach. After identifying possible front-end and back-end OC solutions, a series of OC retailing experiences were examined. These cases were mapped and positioned on two matrices (one for front-end and the other for back-end solutions) where product, network and service drivers were compared to derive insights on the type of retailers more likely to adopt each solution. OC drivers and alternatives were identified through a literature review; informati on about the cases was collected through direct interviews and secondary sources. Four front-end OC solutions (i.e. Click and Collect, InfoStore, InfoCommerce and InStore Support) and three back-end OC solutions (i.e. Store Picking, Warehouse Picking and Dropshipping) were identified. The front-end framework highlights six possible clusters based on product and network complexity. The back-end framework identifies three configurations, grouped by service and product complexity. This paper addresses a meaningful topic, as OC continues to disrupt operations management in most retail segments, from apparel to grocery. The studies in this area are increasing as a signal of growing interest in the theme. Still, most of the extant contributions either focus on logistics underlying OC or front-end aspects separately. This study originally contributes by jointly considering the double back-end and front-end perspectives of OC. This research is also useful for practitioners, as it aims to support retailers in the configuration of their overall OC strategy
Angioedema Phenotypes : Disease Expression and Classification
No full textDue to marked heterogeneity of clinical presentations, comprehensive knowledge of angioedema phenotypes is crucial for correct diagnosis and choosing the appropriate therapeutic approach. One of the ways to a meaningful clinical distinction can be made between forms of angioedema occurring "with or without wheals." Angioedema with wheals (rash) is a hallmark of urticaria, either acute or chronic, spontaneous or inducible. Angioedema without wheals may still be manifested in about 10 % of patients with urticaria, but it may also occur as a separate entity. Several classifications of angioedema as part of urticaria were published over time, while a latest one, released in 2014 (HAWK group consensus, see below), provided a classification of all forms of "angioedema without wheals" distinct from urticaria, which will be the focus of the present review. At this time, the HAWK consensus classification is the best in terms of covering the pathophysiology, mediators involved, angioedema triggers, and clinical expression. According to this classification, three types of hereditary angioedema (genetic C1-INH deficiency, normal C1-INH with factor XII mutations, and unknown origin) and four types of acquired angioedema (C1-INH deficiency, related to ACE inhibitors intake, idiopathic histaminergic, and idiopathic non-histaminergic) are presented. We will review the distinctive clinical features of each phenotype in details
The evaluation of information systems: Lessons learned from practice
No full textIS Performance Management Systems seem to be the right solution for the CIO and IS department's problems, but they are not so widespread in companies due to the difficulties that companies have in the design and implementation process. This paper attempts to address this issue by investigating what factors affect the design and implementation of IS Performance Management Systems and how these factors influence their shape in terms of IS performance dimensions and measures. The majority of previous studies dealing with this issue sought to develop an algorithm for selecting the appropriate dimensions and measures. This scope implied clarity and a willingness to pursue organizational goals and that only one appropriate set of dimensions and measures exists for a company. This paper points out how it is arduous to define such an algorithm because several "soft" factors, e.g. climate and private goals, affect the final shape of IS Performance Systems. © Springer-Verlag 2010
Porous Crystalline Architectures: Ultrafast Molecular Rotors and Dynamics Control by Gas Stimuli (Keynote)
No full textA challenging issue is the dynamics of nanoporous solids after the insertion of molecular rotors in their building blocks,
promising access to the control of rotary motion by chemical and physical stimuli.[1] The combination of porosity
with ultra-fast rotor dynamics was discovered in molecular crystals, covalent organic frameworks and MOFs by 2H
spin-echo NMR spectroscopy and T1 relaxation times.[2-5] The rotors, as fast as 1011 Hz at 150 K, are exposed to the
crystalline channels, which absorb CO2 and I2 from the gas phase, even at low pressures. Interestingly, the rotor dynamics
can be switched on and off by vapor absorption/desorption, showing a remarkable change of material dynamics,
which, in turn, produces a modulated physical response. Novel mesoporous organosiloxane frameworks allowed
us to realize periodic architectures of fast molecular rotors on which C-F dipoles are mounted.[6] These dipolar
rotors showed not only rapid dynamics (109 Hz at 325 K) in the solid-state NMR experiments, but also a dielectric
response typical of a fast dipole reorientation. Moreover, crystals with permanent porosity were exploited
in an unusual way to decorate crystal surfaces with regular arrays of dipolar rotors. The inserted molecules carry alkyl
chains which are included as guests into the channel-ends.[7] The rotors stay at the surface due to a bulky molecular
stopper which prevents the rotors from entering the channels. The host-guest relationships were established by
2D solid-state NMR and GIAO HF ab initio calculations.
In a final example, flexible molecular crystals were fabricated by a series of shape-persistent azobenzene tetramers
that form porous molecular crystals in their trans configuration. The efficient trans→cis photoisomerization of
the azobenzene units converts the crystals into a non-porous phase but crystallinity and porosity are restored upon
Z→E isomerization promoted by visible light irradiation or heating. We demonstrated that the photoisomerization
enables reversible on/off switching of optical properties as well as the capture of CO2 from the gas phase.[8]
We would like to thank Cariplo Foundation, Lombardy Region/INSTM Consortium and MIUR (PRIN 2016).
References:
[1] Comotti, A. et al. (2016). Acc. Chem. Res. 49, 1701-1710.
[2] Bracco, S. et al. (2017). Chem. Eur. J. 23, 11210.
[3] Comotti, A. et al. (2014). J. Am. Chem. Soc. 136, 618.
[4] Comotti, A. et al. (2014). Angew. Chem. Int. Ed. 53, 1043-1047.
[5] Bracco, S. et al. (2017). Chem. Comm. 53, 7776-7779.
[6] Bracco, S. et al. (2015). Angew. Chem. Int Ed. 54, 4773-4777.
[7] Kobr, L. et al. (2012). J. Am. Chem. Soc. 134, 10122-10131.
[8] Baroncini, M. et al. (2015). Nature Chem. 7, 634-640
Integration of a Crop Simulation Model and Remote Sensing Information
No full textThe monitoring of irrigation requirements at district or regional scale can be based on the use of ecological process-based models and remote sensing data. The former simulates the time evolution (usually at daily scale) of the main biophysical variables which determine crop photosynthesis and water consumption rates; the latter allows to provide the spatial distribution of these variables over a region of interest at a time interval ranging from few days to one month. The evaluation of water balance components and, in particular, the estimate of actual evapotranspiration and the partitioning between soil evaporation and plant transpiration, are crucial issues in semi-arid regions where the scarcity of water resources is becoming an important limiting factor crop growth and yield. The research focused an integrated approach to combine field data, simulation crop model and remote sensing information.
Historic data about topography, soil, climate and land cover were collected and organised into a Geographic Information System, which is routinely updated with remotely sensed images. A mechanistic crop growth model has been coupled with the dynamic soil water balance and root uptake model based on finite difference solution of Richards’ equation in order to describe accurately the main crop physiological processes, the soil water fluxes at the interfaces groundwater-soil and soil-atmosphere and water re-distribution in the soil profile. The integration of these two models allows for an improvement of results accuracy for the crop types considered in this study in Mediterranean environmental conditions. Remote sensing images from optical and radar satellite sensors at different spatial scales (from 10 to 50 m) have been collected during crop cycles. Information about land use and leaf area index will be assimilated dynamically by the model, to increase the effectiveness of simulation.
The final product is a Decision Support Systems with the purpose to integrate remote sensing images, to estimate crop and soil variables related to drought, to assimilate these variables into a simulation model at district scale and, finally, to estimate evapotranspiration, plant water status and drought indicators. The structures of the model and Decision Support System are described and the first results of the field and simulation activity are reported
- …
