Las consonantes li´quidas en coreano y espan~ol

Dapena, Jose′-A′lvaro Porto 서울大學校 스페인中南美硏究所 1996 이베로아메리카硏究 Vol.7 No.-

A methodology to derive global maps of leaf traits using remote sensing and climate data

Moreno-Martí,nez, Á,lvaro,Camps-Valls, Gustau,Kattge, Jens,Robinson, Nathaniel,Reichstein, Markus,van Bodegom, Peter,Kramer, Koen,Cornelissen, J. Hans C.,Reich, Peter,Bahn, Michael,Niineme Elsevier 2018 Remote sensing of environment Vol.218 No.-

<P><B>Abstract</B></P> <P>This paper introduces a modular processing chain to derive global high-resolution maps of leaf traits. In particular, we present global maps at 500 m resolution of specific leaf area, leaf dry matter content, leaf nitrogen and phosphorus content per dry mass, and leaf nitrogen/phosphorus ratio. The processing chain exploits machine learning techniques along with optical remote sensing data (MODIS/Landsat) and climate data for gap filling and up-scaling of in-situ measured leaf traits. The chain first uses random forests regression with surrogates to fill gaps in the database (> 45<I>%</I> of missing entries) and maximizes the global representativeness of the trait dataset. Plant species are then aggregated to Plant Functional Types (PFTs). Next, the spatial abundance of PFTs at MODIS resolution (500 m) is calculated using Landsat data (30 m). Based on these PFT abundances, representative trait values are calculated for MODIS pixels with nearby trait data. Finally, different regression algorithms are applied to globally predict trait estimates from these MODIS pixels using remote sensing and climate data. The methods were compared in terms of precision, robustness and efficiency. The best model (random forests regression) shows good precision (normalized RMSE≤ 20<I>%</I>) and goodness of fit (averaged Pearson's correlation R = 0.78) in any considered trait. Along with the estimated global maps of leaf traits, we provide associated uncertainty estimates derived from the regression models. The process chain is modular, and can easily accommodate new traits, data streams (traits databases and remote sensing data), and methods. The machine learning techniques applied allow attribution of information gain to data input and thus provide the opportunity to understand trait-environment relationships at the plant and ecosystem scales. The new data products – the gap-filled trait matrix, a global map of PFT abundance per MODIS gridcells and the high-resolution global leaf trait maps – are complementary to existing large-scale observations of the land surface and we therefore anticipate substantial contributions to advances in quantifying, understanding and prediction of the Earth system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Presented a modular process chain for plant trait mapping including local effects </LI> <LI> High-resolution global maps of leaf traits by fusing measured trait data, LANDSAT and MODIS </LI> <LI> Scope for testing and parameterizing trait-enabled Earth System models </LI> <LI> Implications for land management and Earth system science applications </LI> </UL> </P>

Angular dependence of photoemission time delay in helium

Heuser, Sebastian,Jimé,nez Galá,n, Á,lvaro,Cirelli, Claudio,Marante, Carlos,Sabbar, Mazyar,Boge, Robert,Lucchini, Matteo,Gallmann, Lukas,Ivanov, Igor,Kheifets, Anatoli S.,Dahlstr&oum American Physical Society 2016 Physical Review A Vol.94 No.6

<P>Time delays of electrons emitted from an isotropic initial state with the absorption of a single photon and leaving behind an isotropic ion are angle independent. Using an interferometric method involving XUV attosecond pulse trains and an IR-probe field in combination with a detection scheme, which allows for full three-dimensional momentum resolution, we show that measured time delays between electrons liberated from the 1s(2) spherically symmetric ground state of helium depend on the emission direction of the electrons relative to the common linear polarization axis of the ionizing XUV light and the IR-probing field. Such time delay anisotropy, for which we measure values as large as 60 as, is caused by the interplay between final quantum states with different symmetry and arises naturally whenever the photoionization process involves the exchange of more than one photon. With the support of accurate theoretical models, the angular dependence of the time delay is attributed to small phase differences that are induced in the laser-driven continuum transitions to the final states. Since most measurement techniques tracing attosecond electron dynamics involve the exchange of at least two photons, this is a general and significant effect that must be taken into account in all measurements of time delays involving photoionization processes.</P>

Hypersurface Constrained Elasticae in Lorentzian Space Forms

Garay, Ó,scar J.,Pá,mpano, Á,lvaro,Woo, Changhwa Hindawi Limited 2015 Advances in mathematical physics Vol.2015 No.-

<P>We study geodesics in hypersurfaces of a Lorentzian space formM1n+1(c), which are critical curves of theM1n+1(c)-bending energy functional, for variations constrained to lie on the hypersurface. We characterize critical geodesics showing that they live fully immersed in a totally geodesicM13(c)and that they must be of three different types. Finally, we consider the classification of surfaces in the Minkowski 3-space foliated by critical geodesics.</P>

SMA OBSERVATIONS OF THE W3(OH) COMPLEX: PHYSICAL AND CHEMICAL DIFFERENTIATION BETWEEN W3(H₂O) AND W3(OH)

Qin, Sheng-Li,Schilke, Peter,Wu, Jingwen,Wu, Yuefang,Liu, Tie,Liu, Ying,Sá,nchez-Monge, Á,lvaro IOP Publishing 2015 The Astrophysical journal Vol.803 No.1

<P>We report on the Submillimeter Array (SMA) observations of molecular lines at 270 GHz toward the W3(OH) and W3(H2O) complex. Although previous observations already resolved the W3(H2O) into two or three subcomponents, the physical and chemical properties of the two sources are not well constrained. Our SMA observations clearly resolved the W3(OH) and W3(H2O) continuum cores. Taking advantage of the line fitting tool XCLASS, we identified and modeled a rich molecular spectrum in this complex, including multiple CH3CN and CH3OH transitions in both cores. HDO, C2H5CN, (OCS)-C-13, and vibrationally excited lines of HCN, CH3CN, and CH3OCHO were only detected in W3(H2O). We calculate gas temperatures and column densities for both cores. The results show that W3(H2O) has higher gas temperatures and larger column densities than W3(OH) as previously observed, suggesting physical and chemical differences between the two cores. We compare the molecular abundances in W3(H2O) to those in the Sgr B2(N) hot core, the Orion KL hot core, and the Orion Compact Ridge, and discuss the chemical origin of specific species. An east-west velocity gradient is seen in W3 (H2O), and the extension is consistent with the bipolar outflow orientation traced by water masers and radio jets. A north-south velocity gradient across W3(OH) is also observed. However, with current observations we cannot be assured whether the velocity gradients are caused by rotation, outflow, or radial velocity differences of the subcomponents of W3(OH).</P>

Signatures of minor mergers in the Milky Way disc – I. The SEGUE stellar sample

Gó,mez, Facundo A.,Minchev, Ivan,O’Shea, Brian W.,Lee, Young Sun,Beers, Timothy C.,An, Deokkeun,Bullock, James S.,Purcell, Chris W.,Villalobos, Á,lvaro Blackwell Publishing Ltd 2012 Monthly notices of the Royal Astronomical Society Vol.423 No.4

<P><B>ABSTRACT</B></P><P>It is now known that minor mergers are capable of creating structure in the phase‐space distribution of their host galaxy’s disc. In order to search for such imprints in the Milky Way, we analyse the Sloan Extension for Galactic Understanding and Exploration (SEGUE) F/G dwarf and the Schuster et al. stellar samples. We find similar features in these two completely independent stellar samples, consistent with the predictions of a Milky Way minor‐merger event. We next apply the same analyses to high‐resolution, idealized <I>N</I>‐body simulations of the interaction between the Sagittarius dwarf galaxy and the Milky Way. The energy distributions of stellar particle samples in small spatial regions in the host disc reveal strong variations of structure with position. We find good matches to the observations for models with a mass of Sagittarius’ dark matter halo progenitor <IMG src='/wiley-blackwell_img/lap.gif' alt ='less-than or approximately equal-to'/>10<SUP>11</SUP> M<SUB>⊙</SUB>. Thus, we show that this kind of analysis could be used to provide unprecedentedly tight constraints on Sagittarius’ orbital parameters, as well as place a lower limit on its mass.</P>

Private tutoring and academic achievement in Korea: An approach through PISA-2006

Álvaro Choi,Jorge Calero,Josep-Oriol Escardíbul 한국교육개발원 2012 KEDI Journal of Educational Policy Vol.9 No.2

Although not exclusive to the Republic of Korea’s educational system, the pervasiveness of private tutoring, and its consequences, serve to distinguish it from systems operated in other countries. This paper quantifies the impact of time spent on private tutoring on the performance of students in the three competence fields assessed in the Programme for International Student Assessment (PISA). Instrumental variables are applied in a multilevel framework to address endogeneity. Our results indicate that the impact of time dedicated to private tutoring on academic performance depends on the particular competence: positive for mathematics, positive but decreasing for reading, and non-significant for science.

La noción de precursores en los discursos narrativos a partir de las obras “Japonesas” de Mario Bellatin

Álvaro Martín Navarro 서울대학교 라틴아메리카연구소 2010 이베로아메리카硏究 Vol.21 No.2

El presente ensayo es una propuesta acerca de la homogeneidad de la escritura, a partir de las reflexiones de Jorge Luis Borges que se halla en su obra Kafka y sus precursores. Proponemos la idea de que en cada escritor hay matices y estilos de otros escritores que llegan de forma directa, por medio de sus lecturas, o precursores directos; pero también de forma indirecta, donde los métodos, estéticas y reflexiones, están presentes en diversas obras de esos autores precedentes y en los autores influenciados sin que necesariamente exista una relación causa efecto, por lo que a veces “parecieran” que diversas obras literarias están escritas por la misma mano sin circunscribirse a un espacio o tiempo determinado. Por lo que tenemos dos niveles de precursores, los propios del autor, los leídos, y los propios del sujeto literario, determinado por propuestas culturales, míticas e ideológicas. Tomamos al autor mexicano Mario Bellatin y nos proponemos a presentar estas ideas en una serie de análisis que nacen de sus obras desarrolladas en (su) Japón: Shiki Nagaoka, El jardín de la señora Murakami, Bola negra;paralelamente estableceremos vasos comunicantes entre las obras de Bellatin con algunas obras literarias japoneses, mostrando la idea de precursor en la estructura narrativa del autor por una parte, y del sujeto literario por otra.

Sonographic evaluation of fetal scrotum, testes and epididymis

( Álvaro López Soto ),( Jose Luis Meseguer González ),( María Velasco Martínez ),( Rocío López Pérez ),( Inmaculada Martínez Rivero ),( Mónica Lorente Fernández ),( Olivia García Izquierdo ),( Juan Pe 대한산부인과학회 2021 Obstetrics & Gynecology Science Vol.64 No.5

External male genitalia have rarely been evaluated on fetal ultrasound. Apart from visualization of the penis for fetal sex determination, there are no specific instructions or recommendations from scientific societies. This study aimed to review the current knowledge about prenatal diagnosis of the scrotum and internal structures, with discussion regarding technical aspects and clinical management. We conducted an article search in Medline, EMBASE, Scopus, Google Scholar, and Web of Science databases for studies in English or Spanish language that discussed prenatal scrotal pathologies. We identified 72 studies that met the inclusion criteria. Relevant data were grouped into sections of embryology, ultrasound, pathology, and prenatal diagnosis. The scrotum and internal structures show a wide range of pathologies, with varying degrees of prevalence and morbidity. Most of the reported cases have described incidental findings diagnosed via striking ultrasound signs. Studies discussing normative data or management are scarce.

Western Travelers in Colonial Korea: Foreign Perceptions on Legitimacy of the Japanese Rule and the Two Nations

Álvaro Trigo Maldonado 한국학중앙연구원 한국학중앙연구원 2020 THE REVIEW OF KOREAN STUDIES Vol.23 No.1

This paper analyzes the information contained in a variety of travelogues written prior to and after the Japanese annexation of Korea to provide a better understanding on how Westerners perceived the colonial rule. In order to do so quotes on specific topics such as the socio-political situation of Korea or the traveler’s perception on both Korean and Japanese people have been extracted and juxtaposed in an effort of identifying and defining predominant trends. These primary sources need to be approached taking in consideration the Zeitgeist during the period in the West. Their authors depart from a sociopolitical context during which Social Darwinism was in vogue. Besides that, while taking travelogues as a source of historical information has its limitations it also constitutes an excellent way to discuss to what extent the Japanese propaganda effort in the colony was efficient or not. It is also important to note that most of the travelers arrived into Korea via Japan, stayed at the Japanese-managed Chosun Hotel and they often had very limited interactions with Koreans. Thereby they were exposed to the Japanese discourse. This can be perceived in their comparisons between Korean and Japanese customs. However, I would like to argue how their perception on the latter was still influenced by the orientalist discourse as well.