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Author Escapil-Inchauspe, P.; Jerez-Hanckes, C. doi  openurl
  Title Helmholtz Scattering by Random Domains: First-Order Sparse Boundary Elements Approximation Type Journal Article
  Year 2020 Publication SIAM Journal of Scientific Computing Abbreviated Journal SIAM J. Sci. Comput.  
  Volume to appear Issue Pages  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1064-8275 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1205  
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Author Aylwin, R.; Silva-Oelker, G.; Jerez-Hanckes, C.; Fay, P. doi  openurl
  Title Optimization methods for achieving high diffraction efficiency with perfect electric conducting gratings Type Journal Article
  Year 2020 Publication Journal of the Optical Society of America A Abbreviated Journal J Opt Soc Am A  
  Volume 37 Issue 8 Pages 1316-1326  
  Keywords Beam splitters; Diffraction efficiency; Electron beam lithography; Genetic algorithms; Laser ablation; Quantum cascade semiconductor lasers  
  Abstract This work presents the implementation, numerical examples, and experimental convergence study of first- and second-order optimization methods applied to one-dimensional periodic gratings. Through boundary integral equations and shape derivatives, the profile of a grating is optimized such that it maximizes the diffraction efficiency for given diffraction modes for transverse electric polarization. We provide a thorough comparison of three different optimization methods: a first-order method (gradient descent); a second-order approach based on a Newton iteration, where the usual Newton step is replaced by taking the absolute value of the eigenvalues given by the spectral decomposition of the Hessian matrix to deal with non-convexity; and the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm, a quasi-Newton method. Numerical examples are provided to validate our claims. Moreover, two grating profiles are designed for high efficiency in the Littrow configuration and then compared to a high efficiency commercial grating. Conclusions and recommendations, derived from the numerical experiments, are provided as well as future research avenues.  
  Address  
  Corporate Author Thesis  
  Publisher Osa Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1084-7529 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1204  
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Author Canessa, E.; Chaigneau, S.E.; Lagos, R.; Medina, F.A. doi  openurl
  Title How to carry out conceptual properties norming studies as parameter estimation studies: Lessons from ecology Type Journal Article
  Year 2020 Publication Behavior Research Methods Abbreviated Journal  
  Volume to appear Issue Pages  
  Keywords  
  Abstract Conceptual properties norming studies (CPNs) ask participants to produce properties that describe concepts. From that data, different metrics may be computed (e.g., semantic richness, similarity measures), which are then used in studying concepts and as a source of carefully controlled stimuli for experimentation. Notwithstanding those metrics' demonstrated usefulness, researchers have customarily overlooked that they are only point estimates of the true unknown population values, and therefore, only rough approximations. Thus, though research based on CPN data may produce reliable results, those results are likely to be general and coarse-grained. In contrast, we suggest viewing CPNs as parameter estimation procedures, where researchers obtain only estimates of the unknown population parameters. Thus, more specific and fine-grained analyses must consider those parameters' variability. To this end, we introduce a probabilistic model from the field of ecology. Its related statistical expressions can be applied to compute estimates of CPNs' parameters and their corresponding variances. Furthermore, those expressions can be used to guide the sampling process. The traditional practice in CPN studies is to use the same number of participants across concepts, intuitively believing that practice will render the computed metrics comparable across concepts and CPNs. In contrast, the current work shows why an equal number of participants per concept is generally not desirable. Using CPN data, we show how to use the equations and discuss how they may allow more reasonable analyses and comparisons of parameter values among different concepts in a CPN, and across different CPNs.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1554-3528 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number UAI @ eduardo.moreno @ Canessa2020 Serial 1203  
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Author Sanchez, R.; Villena, M. doi  openurl
  Title Comparative evaluation of wearable devices for measuring elevation gain in mountain physical activities Type Journal Article
  Year 2020 Publication Proceedings Of The Institution Of Mechanical Engineers Part P-Journal Of Sports Engineering And Technology Abbreviated Journal Proc. Inst. Mech. Eng. Part P-J. Sport. Eng. Technol.  
  Volume to appear Issue Pages 8 pp  
  Keywords Mountain running; physical workload; altitude; measuring; validity; GPS; barometric device  
  Abstract The aim of this article is to examine the validity of elevation gain measures in mountain activities, such as hiking and mountain running, using different wearable devices and post-processing procedures. In particular, a total of 202 efforts were recorded and evaluated using three standard devices: GPS watch, GPS watch with barometric altimeter, and smartphone. A benchmark was based on orthorectified aerial photogrammetric survey conducted by the Chilean Air Force. All devices presented considerable elevation gain measuring errors, where the barometric device consistently overestimated elevation gain, while the GPS devices consistently underestimated elevation gain. The incorporation of secondary information in the post-processing can substantially improve the elevation gain measuring accuracy independently of the device and altitude measuring technology, reducing the error from -5% to -1%. These results could help coaches and athletes correct elevation gain estimations using the proposed technique, which would serve as better estimates of physical workload in mountain physical activities.  
  Address [Sanchez, Raimundo; Villena, Marcelo] Adolfo Ibanez Univ, Fac Engn & Sci, Diagonal Las Torres 2640, Santiago 7910000, Chile, Email: raimundo.sanchez@uai.cl  
  Corporate Author Thesis  
  Publisher Sage Publications Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1754-3371 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000534320000001 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1201  
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Author Barrera, J.; Carrasco, R.A.; Moreno, E. doi  openurl
  Title Real-time fleet management decision support system with security constraints Type Journal Article
  Year 2020 Publication TOP Abbreviated Journal TOP  
  Volume to appear Issue Pages 21 pp  
  Keywords Fleet management; Real-time control; Data analytics; GPS tracking; Decision support system; Conflict detection and resolution  
  Abstract Intelligent transportation, and in particular, fleet management, has been a forefront concern for a plethora of industries. This statement is especially true for the production of commodities, where transportation represents a central element for operational continuity. Additionally, in many industries, and in particular those with hazardous environments, fleet control must satisfy a wide range of security restrictions to ensure that risks are kept at bay and accidents are minimum. Furthermore, in these environments, any decision support tool must cope with noisy and incomplete data and give recommendations every few minutes. In this work, a fast and efficient decision support tool is presented to help fleet managers oversee and control ore trucks, in a mining setting. The main objective of this system is to help managers avoid interactions between ore trucks and personnel buses, one of the most critical security constraints in our case study, keeping a minimum security distance between the two at all times. Furthermore, additional algorithms are developed and implemented, so that this approach can work with real-life noisy GPS data. Through the use of historical data, the performance of this decision support system is studied, validating that it works under the real-life conditions presented by the company. The experimental results show that the proposed approach improved truck and road utilization significantly while allowing the fleet manager to control the security distance required by their procedures.  
  Address [Barrera, Javiera; Carrasco, Rodrigo A.; Moreno, Eduardo] Univ Adolfo Ibanez, Fac Engn & Sci, Santiago, Chile, Email: javiera.barrera@uai.cl;  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1134-5764 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000534967700001 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1200  
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Author Munoz, M.; Robles-Navarro, A.; Fuentealba, P.; Cardenas, C. doi  openurl
  Title Predicting Deprotonation Sites Using Alchemical Derivatives Type Journal Article
  Year 2020 Publication Journal Of Physical Chemistry A Abbreviated Journal J. Phys. Chem. A  
  Volume 124 Issue 19 Pages 3754-3760  
  Keywords  
  Abstract An alchemical transformation is any process, physical or fictitious, that connects two points in the chemical space. A particularly important transformation is the vanishing of a proton, whose energy can be linked to the proton dissociation enthalpy of acids. In this work we assess the reliability of alchemical derivatives in predicting the proton dissociation enthalpy of a diverse series of mono- and polyprotic molecules. Alchemical derivatives perform remarkably well in ranking the proton affinity of all molecules. Additionally, alchemical derivatives could be use also as a predictive tool because their predictions correlate quite well with calculations based on energy differences and experimental values. Although second-order alchemical derivatives underestimate the dissociation enthalpy, the deviation seems to be almost constant. This makes alchemical derivatives extremely accurate to evaluate the difference in proton affinity between two acid sites of polyprotic molecule. Finally, we show that the reason for the underestimation of the dissociation enthalpy is most likely the contribution of higher-order derivatives.  
  Address [Robles-Navarro, Andres; Fuentealba, Patricio; Cardenas, Carlos] Univ Chile, Fac Ciencias, Dept Fis, Casilla 653, Santiago, Chile, Email: pfuentea@uchile.cl;  
  Corporate Author Thesis  
  Publisher Amer Chemical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1089-5639 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000535280400008 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1199  
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Author Josserand, C.; Pomeau, Y.; Rica, S. doi  openurl
  Title Finite-time localized singularities as a mechanism for turbulent dissipation Type Journal Article
  Year 2020 Publication Physical Review Fluids Abbreviated Journal Phys. Rev. Fluids  
  Volume 5 Issue 5 Pages 15 pp  
  Keywords  
  Abstract The nature of the fluctuations of the dissipation rate in fluid turbulence is still under debate. One reason may be that the observed fluctuations are strong events of dissipation, which reveal the trace of spatiotemporal singularities of the Euler equations, which are the zero viscosity limit of ordinary incompressible fluids. Viscosity regularizes these hypothetical singularities, resulting in a chaotic fluctuating state in which the strong events appear randomly in space and time, making the energy dissipation highly fluctuating. Yet, to date, it is not known if smooth initial conditions of the Euler equations with finite energy do or do not blow up in finite time. We overcome this central difficulty by providing a scenario for singularity-mediated turbulence based on the self-focusing nonlinear Schrodinger equation. It avoids the intrinsic difficulty of Euler equations since it is well known that solutions of this NLS equation with smooth initial conditions do blow up in finite time. When adding viscosity, the model shows (i) that dissipation takes place near the singularities only, (ii) that such intense events are random in space and time, (iii) that the mean dissipation rate is almost constant as the viscosity varies, and (iv) the observation of an Obukhov-Kolmogorov spectrum with a power-law dependence together with an intermittent behavior using structure function correlations, in close correspondence with the one measured in fluid turbulence.  
  Address [Josserand, Christophe; Pomeau, Yves; Rica, Sergio] CNRS, LadHyX, F-91128 Palaiseau, France, Email: sergio.rica@uai.cl  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-990x ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000535862800004 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1198  
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Author Lagos, F.; Schreiber, M.R.; Parsons, S.G.; Zurlo, A.; Mesa, D.; Gansicke, B.T.; Brahm, R.; Caceres, C.; Canovas, H.; Hernandez, M.S.; Jordan, A.; Koester, D.; Schmidtobreick, L.; Tappert, C.; Zorotovic, M. doi  openurl
  Title The White Dwarf Binary Pathways Survey -III. Contamination from hierarchical triples containing a white dwarf Type Journal Article
  Year 2020 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.  
  Volume 494 Issue 1 Pages 915-922  
  Keywords methods: numerical; methods: statistical; binaries: close; stars: kinematics and dynamics  
  Abstract The White Dwarf Binary Pathways Survey aims at increasing the number of known detached A, F, G, and K main-sequence stars in close orbits with white dwarf companions (WD+AFGK binaries) to refine our understanding about compact binary evolution and the nature of Supernova Ia progenitors. These close WD+AFGK binary stars are expected to form through common envelope evolution, in which tidal forces tend to circularize the orbit. However, some of the identified WD+AFGK binary candidates show eccentric orbits, indicating that these systems are either formed through a different mechanism or perhaps they are not close WD+AFGK binaries. We observed one of these eccentric WD+AFGK binaries with SPHERE and find that the system TYC 7218-934-1 is in fact a triple system where the WD is a distant companion. The inner binary likely consists of the G-type star plus an unseen low-mass companion in an eccentric orbit. Based on this finding, we estimate the fraction of triple systems that could contaminate the WD+AFGK sample. We find that less than 15 per cent of our targets with orbital periods shorter than 100 d might be hierarchical triples.  
  Address [Lagos, F.; Schreiber, M. R.; Hernandez, M-S; Tappert, C.; Zorotovic, M.] Univ Valparaiso, Inst Fis & Astron, Valparaiso, Chile, Email: felipe.lagos@pmigrado.uv.cl;  
  Corporate Author Thesis  
  Publisher Oxford Univ Press Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000535885900070 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1197  
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Author Fernandez, M.; Munoz, F.D.; Moreno, R. doi  openurl
  Title Analysis of imperfect competition in natural gas supply contracts for electric power generation: A closed-loop approach Type Journal Article
  Year 2020 Publication Energy Economics Abbreviated Journal Energy Econ.  
  Volume 87 Issue Pages 15 pp  
  Keywords Market power; Natural gas; Electricity market; Generalized Nash equilibrium; Equilibrium Problem with Equilibrium; Constraints  
  Abstract The supply of natural gas is generally based on contracts that are signed prior to the use of this fuel for power generation. Scarcity of natural gas in systems where a share of electricity demand is supplied with gas turbines does not necessarily imply demand rationing, because most gas turbines can still operate with diesel when natural gas is not available. However, scarcity conditions can lead to electricity price spikes, with welfare effects for consumers and generation firms. We develop a closed-loop equilibrium model to evaluate if generation firms have incentives to contract or import the socially-optimal volumes of natural gas to generate electricity. We consider a perfectly-competitive electricity market, where all firms act as price-takers in the short term, but assume that only a small number of firms own gas turbines and procure natural gas from, for instance, foreign suppliers in liquefied form. We illustrate an application of our model using a network reduction of the electric power system in Chile, considering two strategic firms that make annual decisions about natural gas imports in discrete quantities. We also assume that strategic firms compete in the electricity market with a set of competitive firms do not make strategic decisions about natural gas imports (i.e., a competitive fringe). Our results indicate that strategic firms could have incentives to sign natural gas contracts for volumes that are much lower than the socially-optimal ones, which leads to supernormal profits for these firms in the electricity market. Yet, this effect is rather sensitive to the price of natural gas. A high price of natural gas eliminates the incentives of generation firms to exercise market power through natural gas contracts. (C) 2020 Elsevier B.V. All rights reserved.  
  Address [Fernandez, Mauricio; Munoz, Francisco D.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: fdmunoz@uai.cl  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0140-9883 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000536091600026 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1196  
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Author Kamal, C.; Gravelle, S.; Botto, L. doi  openurl
  Title Hydrodynamic slip can align thin nanoplatelets in shear flow Type Journal Article
  Year 2020 Publication Nature Communications Abbreviated Journal Nat. Commun.  
  Volume 11 Issue 1 Pages 10 pp  
  Keywords  
  Abstract The large-scale processing of nanomaterials such as graphene and MoS2 relies on understanding the flow behaviour of nanometrically-thin platelets suspended in liquids. Here we show, by combining non-equilibrium molecular dynamics and continuum simulations, that rigid nanoplatelets can attain a stable orientation for sufficiently strong flows. Such a stable orientation is in contradiction with the rotational motion predicted by classical colloidal hydrodynamics. This surprising effect is due to hydrodynamic slip at the liquid-solid interface and occurs when the slip length is larger than the platelet thickness; a slip length of a few nanometers may be sufficient to observe alignment. The predictions we developed by examining pure and surface-modified graphene is applicable to different solvent/2D material combinations. The emergence of a fixed orientation in a direction nearly parallel to the flow implies a slip-dependent change in several macroscopic transport properties, with potential impact on applications ranging from functional inks to nanocomposites. Current theories predict that a plate-like particle rotates continuously in a shear flow. Kamal et al. instead show that even nanometric hydrodynamic slip may induce a thin plate-like particle to adopt a stable orientation, and discuss implications of this effect for flow processing of 2D nanomaterials.  
  Address [Kamal, Catherine; Gravelle, Simon; Botto, Lorenzo] Queen Mary Univ London, Sch Engn & Mat Sci, London, England, Email: l.botto@tudelft.nl  
  Corporate Author Thesis  
  Publisher Nature Publishing Group Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2041-1723 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000536569900023 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1195  
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Author Goles, E.; Tsompanas, M.A.; Adamatzky, A.; Tegelaar, M.; Wosten, H.A.B.; Martinez, G.J. doi  openurl
  Title Computational universality of fungal sandpile automata Type Journal Article
  Year 2020 Publication Physics Letters A Abbreviated Journal Phys. Lett. A  
  Volume 384 Issue 22 Pages 8 pp  
  Keywords Fungi; Sandpile automata; Computational universality  
  Abstract Hyphae within the mycelia of the ascomycetous fungi are compartmentalised by septa. Each septum has a pore that allows for inter-compartmental and inter-hyphal streaming of cytosol and even organelles. The compartments, however, have special organelles, Woronin bodies, that can plug the pores. When the pores are blocked, no flow of cytoplasm takes place. Inspired by the controllable compartmentalisation within the mycelium of the ascomycetous fungi we designed two-dimensional fungal automata. A fungal automaton is a cellular automaton where communication between neighbouring cells can be blocked on demand. We demonstrate computational universality of the fungal automata by implementing sandpile cellular automata circuits there. We reduce the Monotone Circuit Value Problem to the Fungal Automaton Prediction Problem. We construct families of wires, cross-overs and gates to prove that the fungal automata are P-complete. (C) 2020 Elsevier B.V. All rights reserved.  
  Address [Goles, Eric; Tsompanas, Michail-Antisthenis; Adamatzky, Andrew; Martinez, Genaro J.] Univ West England, Unconvent Comp Lab, Bristol, Avon, England, Email: andrew.adamatzky@uwe.ac.uk  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0375-9601 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000537033500017 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1194  
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Author Diaz, C.; Belmonte, M.; Campos, J.L.; Franchi, O.; Faundez, M.; Vidal, G.; Argiz, L.; Pedrouso, A.; del Rio, A.V.; Mosquera-Corral, A. doi  openurl
  Title Limits of the anammox process in granular systems to remove nitrogen at low temperature and nitrogen concentration Type Journal Article
  Year 2020 Publication Process Safety And Environmental Protection Abbreviated Journal Process Saf. Environ. Protect.  
  Volume 138 Issue Pages 349-355  
  Keywords Anammox; Dissolved oxygen; Granular biomass; Nitrogen; SRT; Temperature  
  Abstract When partial nitritation-anammox (PN-AMX) processes are applied to treat the mainstream in wastewater treatment plants (WWTPs), it is difficult to fulfil the total nitrogen (TN) quality requirements established by the European Union (<10g TN/m(3)). The operation of the anammox process was evaluated here in a continuous stirred tank reactor operated at 15 degrees C and fed with concentrations of 50 g TN/m(3) (1.30 +/- 0.23 g NO2- -N/g NH4+-N). Two different aspects were identified as crucial, limiting nitrogen removal efficiency. On the one hand, the oxygen transferred from the air in contact with the mixed liquor surface favoured the nitrite oxidation to nitrate (up to 75 %) and this nitrate, in addition to the amount produced from the anammox reaction itself, worsened the effluent quality. On the other hand, the mass transfer of ammonium and nitrite to be converted inside the anammox granules involves relatively large values of apparent affinity constants (k(NH4+app) : 0.50 g NH4+-N/m(3) ; k(NO2-app) 0.17 g NO2--N/m(3)) that favour the presence of these nitrogen compounds in the produced effluent. The careful isolation of the reactor from air seeping and the fixation of right hydraulic and solids retention times are expected to help the maintenance of stability and effluent quality. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.  
  Address [Diaz, Claudia; Belmonte, Marisol] Univ Playa Ancha, Fac Ingn, Lab Biotecnol Medio Ambiente & Ingn LABMAI, Avda Leopoldo Carvallo 270, Valparaiso 2340000, Chile, Email: jluis.campos@uai.cl  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0957-5820 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000538807400005 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1193  
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Author Canessa, E.; Chaigneau, S.E. doi  openurl
  Title Mathematical regularities of data from the property listing task Type Journal Article
  Year 2020 Publication Journal Of Mathematical Psychology Abbreviated Journal J. Math. Psychol.  
  Volume 97 Issue Pages 19 pp  
  Keywords Concepts; Property listing task; Conceptual properties norms; Semantic access  
  Abstract To study linguistically coded concepts, researchers often resort to the Property Listing Task (PLT). In a PLT, participants are asked to list properties that describe a concept (e.g., for DOG, subjects may list “is a pet”, “has four legs”, etc.), which are then coded into property types (i.e., superficially dissimilar properties such as “has four legs” and “is a quadruped” may be coded as “four legs”). When the PLT is done for many concepts, researchers obtain Conceptual Properties Norms (CPNs), which are used to study semantic content and as a source of control variables. Though the PLT and CPNs are widely used across psychology, there is a lack of a formal model of the PLT, which would provide better analysis tools. Particularly, nobody has attempted analyzing the PLT's listing process. Thus, in the current work we develop a mathematical description of the PLT. Our analyses indicate that several regularities should be found in the observable data obtained from a PLT. Using data from three different CPNs (from 3 countries and 2 different languages), we show that these regularities do in fact exist and generalize well across different CPNs. Overall, our results suggest that the description of the regularities found in PLT data may be fruitfully used in the study of concepts. (C) 2020 Elsevier Inc. All rights reserved.  
  Address [Canessa, Enrique; Chaigneau, Sergio E.] Univ Adolfo Ibanez, Ctr Cognit Res CINCO, Sch Psychol, Av Presidente Errazuriz 3328, Santiago, Chile, Email: ecanessa@uai.cl  
  Corporate Author Thesis  
  Publisher Academic Press Inc Elsevier Science Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-2496 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000539438000007 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1192  
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Author Golovach, P.A.; Heggernes, P.; Lima, P.T.; Montealegre, P. doi  openurl
  Title Finding connected secluded subgraphs Type Journal Article
  Year 2020 Publication Journal Of Computer And System Sciences Abbreviated Journal J. Comput. Syst. Sci.  
  Volume 113 Issue Pages 101-124  
  Keywords Secluded subgraph; Parameterized complexity; Forbidden subgraphs  
  Abstract Problems related to finding induced subgraphs satisfying given properties form one of the most studied areas within graph algorithms. However, for many applications, it is desirable that the found subgraph has as few connections to the rest of the graph as possible, which gives rise to the SECLUDED Pi-SUBGRAPH problem. Here, input k is the size of the desired subgraph, and input t is a limit on the number of neighbors this subgraph has in the rest of the graph. This problem has been studied from a parameterized perspective, and unfortunately it turns out to be W[1]-hard for many graph properties Pi, even when parameterized by k + t. We show that the situation changes when we are looking for a connected induced subgraph satisfying Pi. In particular, we show that the CONNECTED SECLUDED Pi-SUBGRAPH problem is FPT when parameterized by just t for many important graph properties Pi. (C) 2020 Elsevier Inc. All rights reserved.  
  Address [Golovach, Petr A.; Heggernes, Pinar; Lima, Paloma T.] Univ Bergen, Dept Informat, N-5020 Bergen, Norway, Email: petr.golovach@uib.no;  
  Corporate Author Thesis  
  Publisher Academic Press Inc Elsevier Science Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-0000 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000539435200006 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1191  
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Author Montealegre, R.; Perez-Salazar, S.; Rapaport, I.; Todinca, I. doi  openurl
  Title Graph reconstruction in the congested clique Type Journal Article
  Year 2020 Publication Journal Of Computer And System Sciences Abbreviated Journal J. Comput. Syst. Sci.  
  Volume 113 Issue Pages 1-17  
  Keywords Distributed computing; Congested clique; Round complexity; Reconstruction problem; Graph classes  
  Abstract In this paper we study the reconstruction problem in the congested clique model. Given a class of graphs g, the problem is defined as follows: if G is not an element of g, then every node must reject; if G is an element of g, then every node must end up knowing all the edges of G. The cost of an algorithm is the total number of bits received by any node through one link. It is not difficult to see that the cost of any algorithm that solves this problem is Omega(log vertical bar g(n)vertical bar/n), where g(n) is the subclass of all n-node labeled graphs in g. We prove that the lower bound is tight and that it is possible to achieve it with only 2 rounds. (C) 2020 Elsevier Inc. All rights reserved.  
  Address [Montealegre, R.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: p.montealegre@edu.uai;  
  Corporate Author Thesis  
  Publisher Academic Press Inc Elsevier Science Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-0000 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000539435200001 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1190  
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Author Crutchik, D.; Franchi, O.; Caminos, L.; Jeison, D.; Belmonte, M.; Pedrouso, A.; Val del Rio, A.; Mosquera-Corral, A.; Campos, J.L. doi  openurl
  Title Polyhydroxyalkanoates (PHAs) Production: A Feasible Economic Option for the Treatment of Sewage Sludge in Municipal Wastewater Treatment Plants? Type Journal Article
  Year 2020 Publication Water Abbreviated Journal Water  
  Volume 12 Issue 4 Pages 12 pp  
  Keywords anaerobic digestion; bioplastics; economic analysis; methane; resource recovery; sewage sludge; WWTP size  
  Abstract Sludge is a by-product of municipal wastewater treatment plants (WWTPs) and its management contributes significantly to the operating costs. Large WWTPs usually have anaerobic sludge digesters to valorize sludge as methane and to reduce its mass. However, the low methane market price opens the possibility for generating other high value-added products from the organic matter in sludge, such as polyhydroxyalkanoates (PHAs). In this work, the economic feasibility of retrofitting two types of WWTPs to convert them into biofactories of crude PHAs was studied. Two cases were analyzed: (a) a large WWTP with anaerobic sludge digestion; and (b) a small WWTP where sludge is only dewatered. In a two-stage PHA-production system (biomass enrichment plus PHAs accumulation), the minimum PHAs cost would be 1.26 and 2.26 US$/kg PHA-crude for the large and small WWTPs, respectively. In a single-stage process, where a fraction of the secondary sludge (25%) is directly used to accumulate PHAs, the production costs would decrease by around 15.9% (small WWTPs) and 19.0% (large WWTPs), since capital costs associated with bioreactors decrease. Sensitivity analysis showed that the PHA/COD (Chemical Oxygen Demand) yield is the most crucial parameter affecting the production costs. The energy, methane, and sludge management prices also have an essential effect on the production costs, and their effect depends on the WWTP's size.  
  Address [Crutchik, Dafne; Franchi, Oscar; Caminos, Luis; Luis Campos, Jose] Univ Adolfo Ibanez, Fac Engn & Sci, Ave Padre Hurtado 750, Vina Del Mar 2520000, Chile, Email: dafne.crutchik@uai.cl;  
  Corporate Author Thesis  
  Publisher Mdpi Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000539527500195 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1189  
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Author Guevara, E.; Babonneau, F.; Homem-de-Mello, T.; Moret, S. doi  openurl
  Title A machine learning and distributionally robust optimization framework for strategic energy planning under uncertainty Type Journal Article
  Year 2020 Publication Applied Energy Abbreviated Journal Appl. Energy  
  Volume 271 Issue Pages 18 pp  
  Keywords Strategic energy planning; Electricity generation; Uncertainty; Distributionally robust optimization; Machine learning  
  Abstract This paper investigates how the choice of stochastic approaches and distribution assumptions impacts strategic investment decisions in energy planning problems. We formulate a two-stage stochastic programming model assuming different distributions for the input parameters and show that there is significant discrepancy among the associated stochastic solutions and other robust solutions published in the literature. To remedy this sensitivity issue, we propose a combined machine learning and distributionally robust optimization (DRO) approach which produces more robust and stable strategic investment decisions with respect to uncertainty assumptions. DRO is applied to deal with ambiguous probability distributions and Machine Learning is used to restrict the DRO model to a subset of important uncertain parameters ensuring computational tractability. Finally, we perform an out-of-sample simulation process to evaluate solutions performances. The Swiss energy system is used as a case study all along the paper to validate the approach.  
  Address [Guevara, Esnil] Univ Adolfo Ibanez, PhD Program Ind Engn & Operat Res, Santiago, Chile, Email: frederic.babonneau@uai.cl  
  Corporate Author Thesis  
  Publisher Elsevier Sci Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0306-2619 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000540436500003 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1188  
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Author Ritt, M.; Pereira, J. doi  openurl
  Title Heuristic and exact algorithms for minimum-weight non-spanning arborescences Type Journal Article
  Year 2020 Publication European Journal Of Operational Research Abbreviated Journal Eur. J. Oper. Res.  
  Volume 287 Issue 1 Pages 61-75  
  Keywords Minimum-weight non-spanning arborescence; Heuristic; Iterated Local Search; Branch-and-cut  
  Abstract We address the problem of finding an arborescence of minimum total edge weight rooted at a given vertex in a directed, edge-weighted graph. If the arborescence must span all vertices the problem is solvable in polynomial time, but the non-spanning version is NP-hard. We propose reduction rules which determine vertices that are required or can be excluded from optimal solutions, a modification of Edmonds algorithm to construct arborescences that span a given set of selected vertices, and embed this procedure into an iterated local search for good vertex selections. Moreover, we propose a cutset-based integer linear programming formulation, provide different linear relaxations to reduce the number of variables in the model and solve the reduced model using a branch-and-cut approach. We give extensive computational results showing that both the heuristic and the exact methods are effective and obtain better solutions on instances from the literature than existing approaches, often in much less time. (C) 2020 Elsevier B.V. All rights reserved.  
  Address [Ritt, Marcus] Univ Fed Rio Grande do Sul, Inst Informat, Av Bento Goncalves 9500, Porto Alegre, RS, Brazil, Email: marcus.ritt@inf.ufrgs.br;  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0377-2217 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000541072800005 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1187  
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Author Baselli, G.; Contreras, F.; Lillo, M.; Marin, M.; Carrasco, R.A. doi  openurl
  Title Optimal decisions for salvage logging after wildfires Type Journal Article
  Year 2020 Publication Omega-International Journal Of Management Science Abbreviated Journal Omega-Int. J. Manage. Sci.  
  Volume 96 Issue Pages 9 pp  
  Keywords Salvage logging; Forest harvesting; Wildfires; Workforce allocation  
  Abstract Strategic, tactical, and operational harvesting plans for the forestry and logging industry have been widely studied for more than 60 years. Many different settings and specific constraints due to legal, environmental, and operational requirements have been modeled, improving the performance of the harvesting process significantly. During the summer of 2017, Chile suffered from the most massive wildfires in its history, affecting almost half a million hectares, of which nearly half were forests owned by medium and small forestry companies. Some of the stands were burned by intense crown fires, which always spread fast, that burned the foliage and outer layer of the bark but left standing dead trees that could be salvage harvested before insect and decay processes rendered them unusable for commercial purposes. Unlike the typical operational programming models studied in the past, in this setting, companies can make insurance claims on part or all of the burnt forest, whereas the rest of the forest needs to be harvested before it loses its value. This problem is known as the salvage logging problem. The issue also has an important social component when considering medium and small forestry and logging companies: most of their personnel come from local communities, which have already been affected by the fires. Harvesting part of the remaining forest can allow them to keep their jobs longer and, hopefully, leave the company in a better financial situation if the harvesting areas are correctly selected. In this work, we present a novel mixed-integer optimization-based approach to support salvage logging decisions, which helps in the configuration of an operational-level harvesting and workforce assignment plan. Our model takes into account the payment from an insurance claim as well as future income from harvesting the remaining trees. The model also computes an optimal assignment of personnel to the different activities required. The objective is to improve the cash position of the company by the end of the harvest and ensure that the company is paying all its liabilities and maintaining personnel. We show how our model performs compared to the current decisions made by medium and small-sized forestry companies, and we study the specific case of a small forestry company located in Cauquenes, Chile, which used our model to decide its course of action. (C) 2019 Elsevier Ltd. All rights reserved.  
  Address [Baselli, Gianluca; Contreras, Felipe; Lillo, Matias; Marin, Magdalena; Carrasco, Rodrigo A.] Univ Adolfo Ibanez, Fac Engn & Sci, Santiago, Chile, Email: gbaselli@alumnos.uai.cl;  
  Corporate Author Thesis  
  Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0305-0483 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000541944700003 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1186  
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Author Argiz, L.; Reyes, C.; Belmonte, M.; Franchi, O.; Campo, R.; Fra-Vazquez, A.; del Rio, A.V.; Mosquera-Corral, A.; Campos, J.L. doi  openurl
  Title Assessment of a fast method to predict the biochemical methane potential based on biodegradable COD obtained by fractionation respirometric tests Type Journal Article
  Year 2020 Publication Journal Of Environmental Management Abbreviated Journal J. Environ. Manage.  
  Volume 269 Issue Pages 9 pp  
  Keywords Anaerobic digestion; Biodegradability; BMP; COD fractionation; Respirometric test  
  Abstract The biochemical methane potential test (BMP) is the most common analytical technique to predict the performance of anaerobic digesters. However, this assay is time-consuming (from 20 to over than 100 days) and consequently impractical when it is necessary to obtain a quick result. Several methods are available for faster BMP prediction but, unfortunately, there is still a lack of a clear alternative. Current aerobic tests underestimate the BMP of substrates since they only detect the easily biodegradable COD. In this context, the potential of COD fractionation respirometric assays, which allow the determination of the particulate slowly biodegradable fraction, was evaluated here as an alternative to early predict the BMP of substrates. Seven different origin waste streams were tested and the anaerobically biodegraded organic matter (CODmet) was compared with the different COD fractions. When considering adapted microorganisms, the appropriate operational conditions and the required biodegradation time, the differences between the CODmet, determined through BMP tests, and the biodegradable COD (CODb) obtained by respirometry, were not significant (CODmet (57.8026 +/- 21.2875) and CODb (55.6491 +/- 21.3417), t (5) = 0.189, p = 0.853). Therefore, results suggest that the BMP of a substrate might be early predicted from its CODb in only few hours. This methodology was validated by the performance of an inter-laboratory studyconsidering four additional substrates.  
  Address [Argiz, L.; Fra-Vazquez, A.; Val del Rio, A.; Mosquera-Corral, A.] Univ Santiago de Compostela, CRETUS Inst, Santiago De Compostela 15782, Galicia, Spain, Email: luciaargiz.montes@usc.es  
  Corporate Author Thesis  
  Publisher Academic Press Ltd- Elsevier Science Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0301-4797 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000541757200008 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 1185  
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