toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Abarzua, N.; Pomareda, R.; Vega, O. pdf  doi
openurl 
  Title Feet in orthogonal-Buekenhout-Metz unitals Type Journal Article
  Year 2018 Publication Advances In Geometry Abbreviated Journal Adv. Geom.  
  Volume 18 Issue 2 Pages 229-236  
  Keywords Unitals; projective planes  
  Abstract Given an orthogonal-Buekenhout-Metz unital U-alpha,U-beta, embedded in PG(2, q(2)), and a point P is not an element of U-alpha,U-beta, we study the set tau(p)(U-alpha,U-beta) of feet of P in U-alpha,U-beta. We characterize geometrically each of these sets as either q + 1 collinear points or as q + 1 points partitioned into two arcs. Other results about the geometry of these sets are also given.  
  Address [Abarzua, N.] Univ Adolfo Ibanez, Santiago, Chile, Email: nicolas.abarzua@uai.cl;  
  Corporate Author Thesis  
  Publisher Walter De Gruyter Gmbh Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1615-715x ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000431397600007 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 852  
Permanent link to this record
 

 
Author Agostini, C.A.; Silva, C.; Nasirov, S. pdf  doi
openurl 
  Title Failure of Energy Mega-Projects in Chile: A Critical Review from Sustainability Perspectives Type Journal Article
  Year 2017 Publication Sustainability Abbreviated Journal Sustainability  
  Volume 9 Issue 6 Pages 17 pp  
  Keywords energy mega-projects; Chile; environmental evaluation; sustainability  
  Abstract A number of successive energy crises over the last decade due to the lack of a balanced investment planning in the energy sector in Chile has led to a strong dependence on external sources and also doubled energy prices in the country, thus posing a significant challenge to the local economy. With the purpose of reaching long-term goals while simultaneously addressing short-term urgencies, Chile seeks to build a consistent and integrated energy policy in order to attract investment in the sector. Despite an overall attractive investment climate and encouraging market conditions in the country, the energy sector has been adversely affected, in particular, by the communities' opposition to mega-projects based on their expected environmental and social impacts. The study highlights recent experiences of energy generation mega-projects in terms of addressing aspects of sustainability. Based on these experiences, it discusses underdeveloped role of environmental evaluations and the main regulatory challenges ahead, recommending then public policies to effectively address these challenges.  
  Address [Agostini, Claudio A.] Univ Adolfo Ibanez, Sch Govt, Ave Diagonal Las Torres 2640, Santiago 7941169, Chile, Email: claudio.agostini@uai.cl;  
  Corporate Author Thesis  
  Publisher Mdpi Ag Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2071-1050 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000404133200195 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 745  
Permanent link to this record
 

 
Author Altimiras, F.; Uszczynska-Ratajczak, B.; Camara, F.; Vlasova, A.; Palumbo, E.; Newhouse, S.; Deacon, R.M.J.; Farias, L.A.E.; Hurley, M.J.; Loyola, D.E.; Vasquez, R.A.; Dobson, R.; Guigo, R.; Cogram, P. doi  openurl
  Title Brain Transcriptome Sequencing of a Natural Model of Alzheimer's Disease Type Journal Article
  Year 2017 Publication Frontiers In Aging Neuroscience Abbreviated Journal Front. Aging Neurosci.  
  Volume 9 Issue Pages 8 pp  
  Keywords Alzheimer's disease; Octodon degus; RNA-seq; gene expression; animal models  
  Abstract  
  Address [Altimiras, Francisco; Farias, Leandro A. E.] Univ Adolfo Ibanez, Fac Sci & Engn, Santiago, Chile, Email: fjaltimiras@gmail.com;  
  Corporate Author Thesis  
  Publisher Frontiers Media Sa Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1663-4365 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000396812400001 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 860  
Permanent link to this record
 

 
Author Anabalon, A.; Astefanesei, D.; Mann, R. pdf  doi
openurl 
  Title Holographic equation of state in fluid/gravity duality Type Journal Article
  Year 2017 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 770 Issue Pages 272-277  
  Keywords  
  Abstract We establish a precise relation between mixed boundary conditions for scalar fields in asymptotically anti de Sitter spacetimes and the equation of state of the dual fluid. We provide a detailed derivation of the relation in the case of five bulk-dimensions for scalar fields saturating the Breitenlohner-Freedman bound. As a concrete example, we discuss the five dimensional scalar-tensor theories describing dark energy in four dimensions. (C) 2017 Published by Elsevier B.V.  
  Address [Anabalon, Andres] Univ Adolfo Ibanez, Fac Artes Liberales, Dept Ciencias, Vina Del Mar, Chile, Email: dastefanesei@gmail.com  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000404196500038 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 743  
Permanent link to this record
 

 
Author Antico, F.C.; Wiener, M.J.; Araya-Letelier, G.; Retamal, R.G. pdf  doi
openurl 
  Title Eco-bricks: a sustainable substitute for construction materials Type Journal Article
  Year 2017 Publication Revista De La Construccion Abbreviated Journal Rev. Constr.  
  Volume 16 Issue 3 Pages 518-526  
  Keywords Eco-bricks; inorganic solid waste valorization; physical characterization; elastic modulus; nonstructural materials  
  Abstract Eco-bricks, polyethylene terephthalate (PET) bottles filled with mixed inorganic waste, have become a low cost construction material and a valid recycling method to reduce waste disposal in regions where industrial recycling is not yet available. Because Eco-bricks are filled with mixed recovered materials, potential recycling of its constituents is difficult at the end of its life. This study proposes considering Eco-bricks filled with a single inorganic waste material to work as a time capsule, with potential for recovering the filling material when other ways of waste valorization are available within those communities that currently have no better recycling options. This paper develops an experimental characterization of density, filler content (by volume), thermal shrinkage, elastic modulus and deformation recovery capacity using four different filler materials: 1) PET; 2) paper & cardboard; 3) tetrapack; and 4) metal. Overall, Eco-brick's density, thermal shrinkage and elastic modulus are dependent on the filler content. Density and elastic modulus of the proposed Eco-bricks are similar to values of medium-high density expanded polystyrene (EPS) used in nonstructural construction, reason why we suggest that these Eco-bricks might be a sustainable alternative to EPS or other nonstructural construction materials.  
  Address [Antico, Federico C.; Gonzalez Retamal, Raul] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Padre Hurtado 750, Vina Del Mar, Chile, Email: federico.antico@uai.cl;  
  Corporate Author Thesis  
  Publisher Pontificia Univ Catolica Chile, Escuela Construccion Civil Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0718-915x ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000418898900016 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 788  
Permanent link to this record
 

 
Author Araujo, J.; Ducoffe, G.; Nisse, N.; Suchan, K. pdf  url
openurl 
  Title On interval number in cycle convexity Type Journal Article
  Year 2018 Publication Discrete Mathematics And Theoretical Computer Science Abbreviated Journal Discret. Math. Theor. Comput. Sci.  
  Volume 20 Issue 1 Pages 35 pp  
  Keywords graph convexity; interval number; domination problems in graphs; complexity and algorithms  
  Abstract Recently, Araujo et al. [Manuscript in preparation, 2017] introduced the notion of Cycle Convexity of graphs. In their seminal work, they studied the graph convexity parameter called hull number for this new graph convexity they proposed, and they presented some of its applications in Knot theory. Roughly, the tunnel number of a knot embedded in a plane is upper bounded by the hull number of a corresponding planar 4-regular graph in cycle convexity. In this paper, we go further in the study of this new graph convexity and we study the interval number of a graph in cycle convexity. This parameter is, alongside the hull number, one of the most studied parameters in the literature about graph convexities. Precisely, given a graph G, its interval number in cycle convexity, denoted by in(cc)(G), is the minimum cardinality of a set S subset of V (G) such that every vertex w is an element of E V (G) \ S has two distinct neighbors u, v is an element of S such that u and v lie in same connected component of G[S], i.e. the subgraph of G induced by the vertices in S. In this work, first we provide bounds on in(cc) (G) and its relations to other graph convexity parameters, and explore its behaviour on grids. Then, we present some hardness results by showing that deciding whetherin(cc) (G) <= k is NP-complete, even if G is a split graph or a bounded-degree planar graph, and that the problem is W[2]-hard in bipartite graphs when k is the parameter. As a consequence, we obtain that in(cc) (G) cannot be approximated up to a constant factor in the classes of split graphs and bipartite graphs (unless P = NP). On the positive side, we present polynomial-time algorithms to compute in(cc) (G) for outerplanar graphs, cobipartite graphs and interval graphs. We also present fixed-parameter tractable (FPT) algorithms to compute it for (q, q – 4)-graphs when q is the parameter and for general graphs G when parameterized either by the treewidth or the neighborhood diversity of G. Some of our hardness results and positive results are not known to hold for related graph convexities and domination problems. We hope that the design of our new reductions and polynomial-time algorithms can be helpful in order to advance in the study of related graph problems.  
  Address [Araujo, Julio] Univ Fed Ceara, Dept Matemat, ParGO, Fortaleza, Ceara, Brazil  
  Corporate Author Thesis  
  Publisher Discrete Mathematics Theoretical Computer Science Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1462-7264 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000431858800001 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 858  
Permanent link to this record
 

 
Author Araya-Letelier, G.; Antico, F.C.; Carrasco, M.; Rojas, P.; Garcia-Herrera, C.M. pdf  doi
openurl 
  Title Effectiveness of new natural fibers on damage-mechanical performance of mortar Type Journal Article
  Year 2017 Publication Construction And Building Materials Abbreviated Journal Constr. Build. Mater.  
  Volume 152 Issue Pages 672-682  
  Keywords Animal fiber; Fiber-reinforced mortar; Mechanical properties; Damage mitigation  
  Abstract Addition of fibers to cement-based materials improve tensile and flexural strength, fracture toughness, abrasion resistance, delay cracking, and reduce crack widths. Natural fibers have recently become more popular in the construction materials community. This investigation addresses the characterization of a new animal fiber (pig hair), a massive food-industry waste worldwide, and its use in mortars. Morphological, physical and mechanical properties of pig hair are determined in order to be used as reinforcement in mortars. A sensitivity analysis on the volumes of fiber in mortars is developed. The results from this investigation showed that reinforced mortars significantly improve impact strength, abrasion resistance, plastic shrinkage cracking, age at cracking, and crack widths as fiber volume increases. Other properties such as compressive and flexural strength, density, porosity and modulus of elasticity of reinforced mortars are not significantly affected by the addition of pig hair. (C) 2017 Elsevier Ltd. All rights reserved.  
  Address [Araya-Letelier, G.; Carrasco, M.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Ave Diagonal Las Torres 2640, Santiago 7941169, Chile, Email: gerardo.araya@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 0950-0618 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000411545600062 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 803  
Permanent link to this record
 

 
Author Araya-Letelier, G.; Concha-Riedel, J.; Antico, F.C.; Valdes, C.; Caceres, G. pdf  doi
openurl 
  Title Influence of natural fiber dosage and length on adobe mixes damage-mechanical behavior Type Journal Article
  Year 2018 Publication Construction And Building Materials Abbreviated Journal Constr. Build. Mater.  
  Volume 174 Issue Pages 645-655  
  Keywords  
  Abstract This study addresses the use of a natural fiber (pig hair), a massive food-industry waste, as reinforcement in adobe mixes (a specific type of earthen material). The relevance of this work resides in the fact that earthen materials are still widely used worldwide because of their low cost, availability, and low environmental impact. Results show that adobe mixes’ mechanical-damage behavior is sensitive to both (i) fiber dosage and (ii) fiber length. Impact strength and flexural toughness are increased, whereas shrinkage distributed crack width is reduced. Average values of compressive and flexural strengths are reduced as fiber dosage and length increase, as a result of porosity generated by fiber clustering. Based on the results of this work a dosage of 0.5% by weight of dry soil using 7&#8239;mm fibers is optimal to improve crack control, flexural toughness and impact strength without statistically affecting flexural and compressive strengths.  
  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 0950-0618 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 865  
Permanent link to this record
 

 
Author Asenjo, F.A.; Comisso, L. pdf  doi
openurl 
  Title Magnetic connections in curved spacetime Type Journal Article
  Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 96 Issue 12 Pages 7 pp  
  Keywords  
  Abstract The ideal magnetohydrodynamic theorem on the conservation of the magnetic connections between plasma elements is generalized to relativistic plasmas in curved spacetime. The connections between plasma elements, which are established by a covariant connection equation, display a particularly complex structure in curved spacetime. Nevertheless, it is shown that these connections can be interpreted in terms of magnetic field lines alone by adopting a 3 + 1 foliation of spacetime.  
  Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago 7941169, Chile, Email: felipe.asenjo@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 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000417759400002 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 785  
Permanent link to this record
 

 
Author Asenjo, F.A.; Comisso, L. pdf  doi
openurl 
  Title Relativistic Magnetic Reconnection in Kerr Spacetime Type Journal Article
  Year 2017 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 118 Issue 5 Pages 5 pp  
  Keywords  
  Abstract The magnetic reconnection process is analyzed for relativistic magnetohydrodynamical plasmas around rotating black holes. A simple generalization of the Sweet-Parker model is used as a first approximation to the problem. The reconnection rate, as well as other important properties of the reconnection layer, has been calculated taking into account the effect of spacetime curvature. Azimuthal and radial current sheet configurations in the equatorial plane of the black hole have been studied, and the case of small black hole rotation rate has been analyzed. For the azimuthal configuration, it is found that the black hole rotation decreases the reconnection rate. On the other hand, in the radial configuration, it is the gravitational force created by the black hole mass that decreases the reconnection rate. These results establish a fundamental interaction between gravity and magnetic reconnection in astrophysical contexts.  
  Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago 7941169, Chile, Email: felipe.asenjo@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 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000396415100005 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 702  
Permanent link to this record
 

 
Author Asenjo, F.A.; Hojman, S.A. pdf  doi
openurl 
  Title Birefringent light propagation on anisotropic cosmological backgrounds Type Journal Article
  Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 96 Issue 4 Pages 12 pp  
  Keywords  
  Abstract Exact electromagnetic wave solutions to Maxwell equations on anisotropic Bianchi I cosmological spacetime backgrounds are studied. The waves evolving on Bianchi I spacetimes exhibit birefringence (associated with linear polarization) and dispersion. The particular case of a vacuum-dominated anisotropic Universe, which reproduces a Friedmann-Robertson-Walker Universe (for late times)-while, for earlier times, it matches a Kasner Universe-is studied. The electromagnetic waves do not, in general, follow null geodesics. This produces a modification of the cosmological redshift, which is then dependent on light polarization, its dispersion, and its non-null geodesic behavior. New results presented here may help to tackle some issues related to the “horizon” problem.  
  Address [Asenjo, Felipe A.; Hojman, Sergio A.] Univ Adolfo Ibanez, UAI Phys Ctr, Santiago 7941169, Chile, Email: felipe.asenjo@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 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000407716200007 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 756  
Permanent link to this record
 

 
Author Asenjo, F.A.; Hojman, S.A. pdf  doi
openurl 
  Title Class of Exact Solutions for a Cosmological Model of Unified Gravitational and Quintessence Fields Type Journal Article
  Year 2017 Publication Foundations Of Physics Abbreviated Journal Found. Phys.  
  Volume 47 Issue 7 Pages 887-896  
  Keywords Quintessence; Exact solution; Unification of geometry and dark matter  
  Abstract A new approach to tackle Einstein equations for an isotropic and homogeneous Friedmann-Robertson-Walker Universe in the presence of a quintessence scalar field is devised. It provides a way to get a simple exact solution to these equations. This solution determines the quintessence potential uniquely and it differs from solutions which have been used to study inflation previously. It relays on a unification of geometry and dark matter implemented through the definition of a functional relation between the scale factor of the Universe and the quintessence field. For a positive curvature Universe, this solution produces perpetual accelerated expansion rate of the Universe, while the Hubble parameter increases abruptly, attains a maximum value and decreases thereafter. The behavior of this cosmological solution is discussed and its main features are displayed. The formalism is extended to include matter and radiation.  
  Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: felipe.asenjo@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 0015-9018 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000404224500003 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 741  
Permanent link to this record
 

 
Author Asenjo, F.A.; Hojman, S.A. pdf  doi
openurl 
  Title Do electromagnetic waves always propagate along null geodesics? Type Journal Article
  Year 2017 Publication Classical And Quantum Gravity Abbreviated Journal Class. Quantum Gravity  
  Volume 34 Issue 20 Pages 12 pp  
  Keywords electromagnetic waves; curved spacetime; non-null geodesics  
  Abstract We find exact solutions to Maxwell equations written in terms of fourvector potentials in non-rotating, as well as in Gdel and Kerr spacetimes. We show that Maxwell equations can be reduced to two uncoupled secondorder differential equations for combinations of the components of the four-vector potential. Exact electromagnetic waves solutions are written on given gravitational field backgrounds where they evolve. We find that in non-rotating spherical symmetric spacetimes, electromagnetic waves travel along null geodesics. However, electromagnetic waves on Gdel and Kerr spacetimes do not exhibit that behavior.  
  Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: felipe.asenjo@uai.cl;  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0264-9381 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000411741800008 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 800  
Permanent link to this record
 

 
Author Asenjo, F.A.; Hojman, S.A. pdf  doi
openurl 
  Title New non-linear modified massless Klein-Gordon equation Type Journal Article
  Year 2017 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C  
  Volume 77 Issue 11 Pages 5 pp  
  Keywords  
  Abstract The massless Klein-Gordon equation on arbitrary curved backgrounds allows for solutions which develop “tails” inside the light cone and, therefore, do not strictly follow null geodesics as discovered by DeWitt and Brehme almost 60 years ago. A modification of the massless Klein-Gordon equation is presented, which always exhibits null geodesic propagation of waves on arbitrary curved space-times. This new equation is derived from a Lagrangian which exhibits current-current interaction. Its non-linearity is due to a self-coupling term which is related to the quantum mechanical Bohm potential.  
  Address [Asenjo, Felipe A.; Hojman, Sergio A.] Univ Adolfo Ibanez, UAI Phys Ctr, Santiago, Chile, Email: felipe.asenjo@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 1434-6044 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000414439100003 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 791  
Permanent link to this record
 

 
Author Asenjo, F.A.; Comisso, L.; Mahajan, S.M. pdf  doi
openurl 
  Title Generalized magnetofluid connections in pair plasmas Type Journal Article
  Year 2015 Publication Physics Of Plasmas Abbreviated Journal Phys. Plasmas  
  Volume 22 Issue 12 Pages 4 pp  
  Keywords  
  Abstract We extend the magnetic connection theorem of ideal magnetohydrodynamics to nonideal relativistic pair plasmas. Adopting a generalized Ohm's law, we prove the existence of generalized magnetofluid connections that are preserved by the plasma dynamics. We show that these connections are related to a general antisymmetric tensor that unifies the electromagnetic and fluid fields. The generalized magnetofluid connections set important constraints on the plasma dynamics by forbidding transitions between configurations with different magnetofluid connectivity. An approximated solution is explicitly shown where the corrections due to current inertial effects are found. (C) 2015 AIP Publishing LLC.  
  Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago 7941169, Chile, Email: felipe.asenjo@uai.cl;  
  Corporate Author Thesis  
  Publisher Amer Inst Physics Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1070-664x ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000367460400019 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 573  
Permanent link to this record
 

 
Author Asenjo, F.A.; Erices, C.; Gomberoff, A.; Hojman, S.A.; Montecinos, A. pdf  doi
openurl 
  Title Differential geometry approach to asymmetric transmission of light Type Journal Article
  Year 2017 Publication Optics Express Abbreviated Journal Opt. Express  
  Volume 25 Issue 22 Pages 26405-26416  
  Keywords  
  Abstract In the last ten years, the technology of differential geometry, ubiquitous in gravitational physics, has found its place in the field of optics. It has been successfully used in the design of optical metamaterials through a technique now known as “transformation optics.” This method, however, only applies for the particular class of metamaterials known as impedance matched, that is, materials whose electric permittivity is equal to their magnetic permeability. In that case, the material may be described by a spacetime metric. In the present work we will introduce a generalization of the geometric methods of transformation optics to situations in which the material is not impedance matched. In such situations, the material -or more precisely, its constitutive tensor-will not be described by a metric only. We bring in a second tensor, with the local symmetries of the Weyl tensor, the “W-tensor.” In the geometric optics approximation we show how the properties of the W-tensor are related to the asymmetric transmission of the material. We apply this feature to the design of a particularly interesting set of asymmetric materials. These materials are birefringent when light rays approach the material in a given direction, but behave just like vacuum when the rays have the opposite direction with the appropriate polarization (or, in some cases, independently of the polarization). (C) 2017 Optical Society of America  
  Address [Asenjo, Felipe A.; Gomberoff, Andres] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Av Diagonal Torres 2640, Santiago, Chile, Email: andres.gomberoff@uai.cl  
  Corporate Author Thesis  
  Publisher Optical Soc Amer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1094-4087 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000413995000004 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 798  
Permanent link to this record
 

 
Author Atkinson, J.; Maurelia, A. pdf  doi
openurl 
  Title Redundancy-Based Trust in Question-Answering Systems Type Journal Article
  Year 2017 Publication Computer Abbreviated Journal Computer  
  Volume 50 Issue 1 Pages 58-65  
  Keywords  
  Abstract By combining user preferences, redundancy analysis, and trust-network inference, the proposed trust model can augment candidate answers with information about target sources on the basis of connections with other web users and sources. Experiments show that the model is more effective overall than trust analyses based on inference alone.  
  Address [Atkinson, John] Univ Adolfo Ibanez, Fac Sci & Engn, Santiago, Region Metropol, Chile, Email: john.atkinson@uai.cl;  
  Corporate Author Thesis  
  Publisher Ieee Computer Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0018-9162 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000393792800009 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 703  
Permanent link to this record
 

 
Author Barrera, J.; Moreno, E.; Varas K., S. doi  openurl
  Title A decomposition algorithm for computing income taxes with pass-through entities and its application to the Chilean case Type Journal Article
  Year 2018 Publication Annals Of Operations Research Abbreviated Journal Ann. Oper. Res.  
  Volume to appear Issue Pages  
  Keywords  
  Abstract Income tax systems with “pass-through” entities transfer a firm's incomes to the sharehold- ers, which are taxed individually. In 2014, a Chilean tax reform introduced this type of entity and changed to an accrual basis that distributes incomes (but not losses) to shareholders. A crucial step for the Chilean taxation authority is to compute the final income of each individual, given the complex network of corporations and companies, usually including cycles between them. In this paper, we show the mathematical conceptualization and the solution to the problem, proving that there is only one way to distribute incomes to taxpayers. Using the theory of absorbing Markov chains, we define a mathematical model for computing the taxable incomes of each taxpayer, and we propose a decomposition algorithm for this problem. This allows us to compute the solution accurately and with the efficient use of computational resources. Finally, we present some characteristics of the Chilean taxpayers' network and computational results of the algorithm using this network.  
  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 0254-5330 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 767  
Permanent link to this record
 

 
Author Barros, M.; Galea, M.; Leiva, V.; Santos-Neto, M. pdf  doi
openurl 
  Title Generalized Tobit models: diagnostics and application in econometrics Type Journal Article
  Year 2018 Publication Journal Of Applied Statistics Abbreviated Journal J. Appl. Stat.  
  Volume 45 Issue 1 Pages 145-167  
  Keywords Cook distance; elliptically contoured distributions; labor supply data; local influence method; maximum likelihood method; R software; residuals; Student-t distribution  
  Abstract The standard Tobit model is constructed under the assumption of a normal distribution and has been widely applied in econometrics. Atypical/extreme data have a harmful effect on the maximum likelihood estimates of the standard Tobit model parameters. Then, we need to count with diagnostic tools to evaluate the effect of extreme data. If they are detected, we must have available a Tobit model that is robust to this type of data. The family of elliptically contoured distributions has the Laplace, logistic, normal and Student-t cases as some of its members. This family has been largely used for providing generalizations of models based on the normal distribution, with excellent practical results. In particular, because the Student-t distribution has an additional parameter, we can adjust the kurtosis of the data, providing robust estimates against extreme data. We propose a methodology based on a generalization of the standard Tobit model with errors following elliptical distributions. Diagnostics in the Tobit model with elliptical errors are developed. We derive residuals and global/local influence methods considering several perturbation schemes. This is important because different diagnostic methods can detect different atypical data. We implement the proposed methodology in an R package. We illustrate the methodology with real-world econometrical data by using the R package, which shows its potential applications. The Tobit model based on the Student-t distribution with a small quantity of degrees of freedom displays an excellent performance reducing the influence of extreme cases in the maximum likelihood estimates in the application presented. It provides new empirical evidence on the capabilities of the Student-t distribution for accommodation of atypical data.  
  Address [Barros, Michelli; Santos-Neto, Manoel] Univ Fed Campina Grande, Dept Stat, Campina Grande, Brazil, Email: victorleivasanchez@gmail.com  
  Corporate Author Thesis  
  Publisher Taylor & Francis Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0266-4763 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000415929600011 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 781  
Permanent link to this record
 

 
Author Basu, S.; Yawar, A.; Concha, A.; Bandi, M.M. pdf  doi
openurl 
  Title On angled bounce-off impact of a drop impinging on a flowing soap film Type Journal Article
  Year 2017 Publication Fluid Dynamics Research Abbreviated Journal Fluid Dyn. Res.  
  Volume 49 Issue 6 Pages 19 pp  
  Keywords drop impact; soap film; interfacial flow; bouncing drops  
  Abstract Small drops impinging obliquely on thin flowing soap films frequently demonstrate the rare emergence of bulk elastic effects working in-tandem with the more commonplace hydrodynamic interactions. Three collision regimes are observable: (a) drop piercing through the film, (b) it coalescing with the flow, and (c) it bouncing off the film surface. During impact, the drop deforms along with a bulk elastic deformation of the film. For impacts that are close-to-tangential, the bounce-off regime predominates. We outline a reduced order analytical framework assuming a deformable drop and a deformable three-dimensional film, and the idealization invokes a phase-based parametric study. Angular inclination of the film and the ratio of post and pre-impact drop sizes entail the phase parameters. We also perform experiments with vertically descending droplets (constituted from deionized water) impacting against an inclined soap film, flowing under constant pressure head. Model-predicted phase domain for bounce-off compares well to our experimental findings. Additionally, the experiments exhibit momentum transfer to the film in the form of shed vortex dipoles, along with propagation of free surface waves. On consulting prior published work, we note that for locomotion of water-walking insects using an impulsive action, the momentum distribution to the shed vortices and waves are both significant, taking up respectively 2/3 and 1/3 of the imparted streamwise momentum. Considering the visually similar impulse actions, this theory, despite its assumption of a quiescent liquid bath of infinite depth, is applied to the drop bounce-off experiments, and the resultant shed vortex dipole momenta are compared to the momenta of the coherent vortex structures computed from particle imaging velocimetry data. The magnitudes reveal identical order (10(-7) N s), suggesting that notwithstanding the disparities, the bounce-off regime may be tapped as a toy analog for impulse-based interfacial biolocomotion.  
  Address [Basu, Saikat; Yawar, Ali; Bandi, M. M.] Okinawa Inst Sci & Technol, Grad Univ, Collect Interact Unit, Onna Son, Okinawa 9040495, Japan, Email: saikat_basu@med.unc.edu  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0169-5983 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000415620000002 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 789  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: