bluuebunny/crossref_metadata_2025_split huggingface dataset:
Valoración del riesgo de caries infantil en un servicio hospitalario de urgencias
Authors: Crovetto Martínez Rafael , Ortuzar Otxoa Leyre , Martinez Rodriguez Adelina , Fernández Alonso Julia , Escobar-Martínez Antonio 
Published: February 2016

La caries es una destrucción de los tejidos mineralizados del diente, siendo la enfermedad crónica más prevalente del niño. <br /><br />Objetivos: Determinar, mediante un estudio de enfermería, la prevalencia de riesgo de caries en los niños que acuden a un Servicio de Urgencias Hospitalarias. <br /><br />Método: Aplicación del formulario validado para la evaluación de riesgo de caries propuesto por la Sociedad Americana de Odontopediatría, con 14 ítems para niños de más de 7 años y 13 ítems en menores de esa edad. La aplicación de dicho formulario ha contemplado la caducidad de la dentición temporal en relación a la edad del niño estudiado. <br /><br />Resultados: El formulario se ha completado en 101 niños. El 72.7% de los niños menores de 7 años y el 89.1% de los mayores de 7 años presentan uno o más factores de alto riesgo para caries infantil, existiendo diferencias notables en los resultados, en función del origen de los niños o de su etnia. Los peores resultados los ofrecen los niños gitanos cuyo riesgo de caries es el 100% en grupos de cualquier edad. <br /><br />Conclusiones: Hemos determinado mediante un estudio de enfermería, la prevalencia de riesgo de caries infantil. La Enfermería española puede y debe asumir un papel activo en la promoción de la salud oral infantil, aplicando activamente sus conocimientos<br /><br />
Competencias y entorno clinico de aprendizaje en enfermería: autopercepcion de estudiantes avanzados de Uruguay
Authors: De Souza Cruz María Cecilia , Mariscal Crespo Maria Isabel 
Published: February 2016

<p>Objetivo: El objetivo del presente trabajo fue describir la percepción del nivel de competencias en relación con el entorno de aprendizaje práctico, por estudiantes de enfermería de Uruguay. <br /><br />Material y Métodos: Se realizó un estudio observacional, descriptivo, transversal interviniendo 33 estudiantes del último ciclo de Facultad de Enfermería de Universidad de la República y Universidad Católica del Uruguay. Los datos se recolectaron en el año 2013 utilizando dos instrumentos previamente validados, el Nurse Competence Scale y el Practice Environment Scale-Nursing Work Index. <br /><br />Resultados: El nivel global de competencias percibido por los estudiantes es Muy Bueno (76.97; VAS: 0-100). La dimensión autoevaluada como más alta fue Rol de Trabajo. La frecuencia de utilización de competencias se ubicó en su mayoría (84.8%) entre utilizadas “muy a menudo” y “ocasionalmente”. El entorno se evaluó mayormente como no favorable (54.5% en desacuerdo). No se pudo establecer relación entre competencias y entorno para la muestra estudiada. <br /><br />Conclusiones: Los estudiantes avanzados tienen un muy buen nivel de competencias. La autoevaluación, a través de instrumentos como el NCS, es una herramienta fundamental para la evaluación de las competencias alcanzadas. Es imprescindible continuar investigando acerca del entorno y otros factores que puedan influir en las competencias<br /><em><br /></em></p>
An Expressively Complete Linear Time Temporal Logic for Mazurkiewicz Traces
Authors: Thiagarajan P. S. , Walukiewicz Igor 
Published: February 2016

<p>A basic result concerning LTL, the propositional temporal logic of linear time, is that it is expressively complete; it is equal in expressive power to the first order theory of sequences. We present here a smooth extension of this result to the class of partial orders known as Mazurkiewicz traces. These partial orders arise in a variety of contexts in concurrency theory and they provide the conceptual basis for many of the partial order reduction methods that have been developed in connection with LTL-specifications.</p><p>We show that LTrL, our linear time temporal logic, is equal in expressive power to the first order theory of traces when interpreted over (finite and) infinite traces. This result fills a prominent gap in the existing logical theory of infinite traces. LTrL also provides a syntactic characterisation of the so-called trace consistent (robust) LTL-specifications. These are specifications expressed as LTL formulas that do not distinguish between different linearisations of the same trace and hence are amenable to partial order reduction methods.</p>
Lower Bounds for Dynamic Transitive Closure, Planar Point Location, and Parentheses Matching
Authors: Husfeldt Thore , Rauhe Theis , Skyum Søren 
Published: February 2016

We give a number of new lower bounds in the cell probe model<br />with logarithmic cell size, which entails the same bounds on the random access computer with logarithmic word size and unit cost operations. We study the signed prefix sum problem: given a string of length n of zeroes and signed ones, compute the sum of its ith prefix during updates. We show a<br />lower bound of Omega(log n/log log n) time per operations, even if the prefix sums are bounded by log n/log log n during all updates. We also show that if the update time is bounded by the product of the worst-case update time and the<br />answer to the query, then the update time must be Omega(sqrt(log n/ log log n)).<br /> These results allow us to prove lower bounds for a variety of seemingly unrelated<br />dynamic problems. We give a lower bound for the dynamic planar point location in monotone subdivisions of <br />Omega(log n/ log log n) per operation. We give<br />a lower bound for the dynamic transitive closure problem on upward planar graphs with one source and one sink of <br />Omega(log n/(log logn)^2) per operation. We give a lower bound of Omega(sqrt(log n/log log n)) for the dynamic membership problem of any Dyck language with two or more letters. This implies the same<br />lower bound for the dynamic word problem for the free group with k generators. We also give lower bounds for the dynamic prefix majority and prefix equality problems.
Lower Bounds for Dynamic Algebraic Problems
Authors: Frandsen Gudmund Skovbjerg , Hansen Johan P. , Miltersen Peter Bro 
Published: February 2016

We consider dynamic evaluation of algebraic functions (matrix multiplication, determinant, convolution, Fourier transform, etc.) in the model of Reif and Tate; i.e., if f(x1, . . . , xn) = (y1, . . . , ym) is an algebraic problem, we consider serving on-line requests of the form "change input xi to value v" or "what is the value of output yi?". We present techniques for showing lower bounds on the worst case time complexity per operation for such problems. The first gives lower bounds in a wide range of rather powerful models (for instance history dependent<br />algebraic computation trees over any infinite subset of a field, the integer RAM, and the generalized real RAM model of Ben-Amram and Galil). Using this technique, we show optimal Omega(n) bounds for dynamic matrix-vector product, dynamic matrix multiplication and dynamic discriminant and an <br />Omega(sqrt(n)) lower bound for dynamic polynomial multiplication (convolution), providing a good match with Reif and<br />Tate's O(sqrt(n log n)) upper bound. We also show linear lower bounds for dynamic determinant, matrix adjoint and matrix inverse and an Omega(sqrt(n)) lower bound for the elementary symmetric functions. The second technique is the communication complexity technique of Miltersen, Nisan, Safra, and Wigderson which we apply to the setting<br />of dynamic algebraic problems, obtaining similar lower bounds in the word RAM model. The third technique gives lower bounds in the weaker straight line program model. Using this technique, we show an ((log n)2= log log n) lower bound for dynamic discrete Fourier transform. Technical ingredients of our techniques are the incompressibility technique of Ben-Amram and Galil and the lower bound for depth-two superconcentrators of Radhakrishnan and Ta-Shma. The incompressibility technique is extended to arithmetic computation in arbitrary fields.
The Hardness of Speeding-up Knapsack
Authors: Sen Sandeep 
Published: February 2016

We show that it is not possible to speed-up the Knapsack problem efficiently in the parallel algebraic decision tree model. More specifically, we prove that any parallel algorithm in the fixed degree algebraic decision tree model that solves the decision version of the Knapsack problem requires Omega(sqrt(n)) rounds even by using 2^sqrt(n) processors. We extend the result to the PRAM model without bit-operations. These results are consistent with Mulmuley's recent result on the separation of the strongly-polynomial class and the corresponding NC class in the arithmetic PRAM model.<br />Keywords lower-bounds, parallel algorithms, algebraic decision tree
Proving in Zero-Knowledge that a Number is the Product of Two Safe Primes
Authors: Camenisch Jan , Michels Markus 
Published: February 2016

<p>This paper presents the first efficient statistical zero-knowledge protocols to prove statements such as:<br />A committed number is a pseudo-prime.<br />A committed (or revealed) number is the product of two safe primes, i.e., primes p and q such that (p - 1)=2 and (q - 1)=2 are primes as well.<br />A given value is of large order modulo a composite number that consists of two safe prime factors.</p><p>So far, no methods other than inefficient circuit-based proofs are known for proving such properties. Proving the second property is for instance necessary in many recent cryptographic schemes that rely on both the hardness of computing discrete logarithms and of difficulty computing roots modulo a composite.<br />The main building blocks of our protocols are statistical zero-knowledge proofs that are of independent interest. Mainly, we show how to prove the correct computation of a modular addition, a modular multiplication, or a modular exponentiation, where all values including the modulus are committed but not<br />publicly known. Apart from the validity of the computation, no other information about the modulus (e.g., a generator which order equals the modulus) or any other operand is given. Our technique can be generalized to prove in zeroknowledge<br />that any multivariate polynomial equation modulo a certain modulus is satisfied, where only commitments to the variables of the polynomial and a commitment to the modulus must be known. This improves previous results,<br />where the modulus is publicly known.<br />We show how a prover can use these building blocks to convince a verifier that a committed number is prime. This finally leads to efficient protocols for proving that a committed (or revealed) number is the product of two safe primes. As a consequence, it can be shown that a given value is of large order modulo a<br />given number that is a product of two safe primes.</p><p> </p><p>Keywords. RSA-based protocols, zero-knowledge proofs of knowledge, primality tests.</p>
Lambda-Dropping: Transforming Recursive Equations into Programs with Block Structure
Authors: Danvy Olivier , Schultz Ulrik P. 
Published: February 2016

Lambda-lifting a block-structured program transforms it into a set of recursive equations. We present the symmetric transformation: lambda-dropping. Lambda-dropping a set of recursive equations restores block structure and lexical scope.<br /> <br />For lack of block structure and lexical scope, recursive equations must carry around all the parameters that any of their callees might possibly need. Both lambda-lifting and lambda-dropping thus require one to compute Def/Use paths:<ul><li>for lambda-lifting: each of the functions occurring in the path of a free variable is passed this variable as a parameter;</li><li>for lambda-dropping: parameters which are used in the same scope as their definition do not need to be passed along in their path.</li></ul>A program whose blocks have no free variables is scope-insensitive. Its blocks are then free to float (for lambda-lifting) or to sink (for lambda-dropping) along the vertices of the scope tree.<br /> <br />Our primary application is partial evaluation. Indeed, many partial evaluators for procedural programs operate on recursive equations. To this end, they lambda-lift source programs in a pre-processing phase. But often, partial evaluators [automatically] produce residual recursive equations with dozens of parameters, which most compilers do not handle efficiently. We solve this critical problem by lambda-dropping residual programs in a post-processing phase, which significantly improves both their compile time and their run time.<br /> <br /> Lambda-lifting has been presented as an intermediate transformation in compilers for functional languages. We study lambda-lifting and lambda-dropping per se, though lambda-dropping also has a use as an intermediate transformation in a compiler: we noticed that lambda-dropping a program corresponds to transforming it into the functional representation of its optimal SSA form. This observation actually led us to substantially improve our PEPM '97 presentation of lambda-dropping.<br /><br />Superseded by BRICS-RS-99-27.
Weak Bisimulation and Open Maps
Authors: Fiore Marcelo P. , Cattani Gian Luca , Winskel Glynn 
Published: February 2016

<p>A systematic treatment of weak bisimulation and observational congruence<br />on presheaf models is presented. The theory is developed with<br />respect to a "hiding" functor from a category of paths to observable<br />paths. Via a view of processes as bundles, we are able to account for<br />weak morphisms (roughly only required to preserve observable paths)<br />and to derive a saturation monad (on the category of presheaves over<br />the category of paths). Weak morphisms may be encoded as strong<br />ones via the Kleisli construction associated to the saturation monad.<br />A general notion of weak open-map bisimulation is introduced, and<br />results relating various notions of strong and weak bisimulation are<br />provided. The abstract theory is accompanied by the concrete study<br />of two key models for concurrency, the interleaving model of synchronisation<br /> trees and the independence model of labelled event structures.</p><p>To appear in Proceedings of the 14th Annual IEEE Symposium on Logic<br />in Computer science, LICS'99, IEEE Press, July 1999.</p><p> </p>
On the Steiner Tree 3/2-Approximation for Quasi-Bipartite Graphs
Authors: Rizzi Romeo 
Published: February 2016

<p>Let G = (V,E) be an undirected simple graph and w : E -> R+ be<br />a non-negative weighting of the edges of G. Assume V is partitioned<br />as R union X. A Steiner tree is any tree T of G such that every node<br />in R is incident with at least one edge of T. The metric Steiner tree<br />problem asks for a Steiner tree of minimum weight, given that w is a<br />metric. When X is a stable set of G, then (G,R,X) is called quasi-bipartite.<br /> In [1], Rajagopalan and Vazirani introduced the notion of<br />quasi-bipartiteness and gave a ( 3/2 + epsilon) approximation algorithm<br /> for the metric Steiner tree problem, when (G,R,X) is quasi-bipartite. In this<br />paper, we simplify and strengthen the result of Rajagopalan and Vazirani.<br />We also show how classical bit scaling techniques can be adapted<br />to the design of approximation algorithms.</p><p>Key words: Steiner tree, local search, approximation algorithm, bit scaling.</p><p> </p>
Improved Bounds for Dictionary Look-up with One Error
Authors: Brodal Gerth Stølting , Venkatesh Srinivasan 
Published: February 2016

<p>Given a dictionary S of n binary strings each of length m,<br />we consider the problem of designing a data structure for S that<br />supports d-queries; given a binary query string q of length m, a<br />d-query reports if there exists a string in S within Hamming <br />distance d of q. We construct a data structure for the case d = 1, that<br />requires space O(n log m) and has query time O(1) in a cell probe<br />model with word size m. This generalizes and improves the <br />previous bounds of Yao and Yao for the problem in the bit probe<br />model.</p><p>Keywords: Data Structures, Dictionaries, Hashing, Hamming Distance</p><p> </p>
Optimal Resilient Dynamic Dictionaries
Authors: Brodal Gerth Stølting , Fagerberg Rolf , Jørgensen Allan Grønlund , Moruz Gabriel , Mølhave Thomas 
Published: February 2016

<p>We investigate the problem of computing in the presence of faults that may arbitrarily (i.e., adversarily) corrupt memory locations. In the faulty memory model, any memory cell can get corrupted at any time, and corrupted cells cannot be distinguished from uncorrupted ones. An upper bound delta on the number of corruptions and O(1) reliable memory cells are provided. In this model, we focus on the design of resilient dictionaries, i.e., dictionaries which are able to operate correctly (at least) on the set of uncorrupted keys. We first present a simple resilient dynamic search tree, based on random sampling, with O(log n + delta) expected amortized cost per operation, and O(n) space complexity. We then propose an optimal deterministic static dictionary supporting searches in Theta(log n + delta) time in the worst case, and we show how to use it in a dynamic setting in order to support updates in O(log n + delta) amortized time. Our dynamic dictionary also supports range queries in O(log n + delta + t) worst case time, where t is the size of the output. Finally, we show that every resilient search tree (with some reasonable properties) must take Omega(log n + delta) worst-case time per search.</p><p> </p><p>Full text: <a href="http://dx.doi.org/10.1007/978-3-540-75520-3_32" target="_self">http://dx.doi.org/10.1007/978-3-540-75520-3_32</a></p>
Fixed Points on Abstract Structures without the Equality Test
Authors: Korovina Margarita 
Published: February 2016

In this paper we present a study of definability properties of fixed points of effective operators on abstract structures without the equality test. In particular we prove that Gandy theorem holds for abstract structures. This provides a useful tool for dealing with recursive definitions using Sigma-formulas.<br /> <br />One of the applications of Gandy theorem in the case of the reals without the equality test is that it allows us to define universal Sigma-predicates. It leads to a topological characterisation of Sigma-relations on |R.
Equational Axioms for Probabilistic Bisimilarity (Preliminary Report)
Authors: Aceto Luca , Ésik Zoltán , Ingólfsdóttir Anna 
Published: February 2016

This paper gives an equational axiomatization of probabilistic bisimulation equivalence for a class of finite-state agents previously studied by Stark and Smolka ((2000) <em>Proof, Language, and Interaction: Essays in Honour of Robin Milner</em>, pp. 571-595). The axiomatization is obtained by extending the general axioms of iteration theories (or iteration algebras), which characterize the equational properties of the fixed point operator on (omega-)continuous or monotonic functions, with three axiom schemas that express laws that are specific to probabilistic bisimilarity. Hence probabilistic bisimilarity (over finite-state agents) has an equational axiomatization relative to iteration algebras.
Klassisk musik som identitet. En præsentation af temaer i publicerede selvbiografier
Authors: Koudal Jens Henrik 
Published: February 2016

<p> </p><p>Empirisk baserede studier af musik og identitet udføres ofte på basis af inter- views, spørgeskemaer, kliniske musikterapi-sessioner, deltagerobservation eller musikterapi-studenters korte, utrykte beretninger om musikken i deres eget liv. I denne artikel bygger forfatteren derimod på publicerede selvbiografier. Artiklen beskriver og diskuterer, hvordan trykte selvbiografier fra tre dirigenter kan forstås som udtryk for disse musikeres identitet. Hvilke temaer fra erindringen vælger de at fremdrage i selvbiografierne? Hvordan giver de deres liv mening ved at fortælle om det i en selvbiografi? Ved at kombinere en musikpsykologisk og en hermeneu- tisk-litterær tilgang når artiklen frem til, at det på basis af de tre selvbiografier er muligt at skitsere disse tre individuelle musiker-identiteter. Selvbiografiens styr- ke er i denne sammenhæng, at den er en fortælling om hele livet, der giver livet mening, formuleret af hovedpersonen. Som hovedpersonens selvrepræsentation fortjener den opmærksomhed.</p>
Growth and characterization of indium doped silicon single crystals at industrial scale
Authors: Haringer Stephan , Giannattasio Armando , Alt Hans Christian , Scala Roberto 
Published: February 2016

Abstract
Indium is becoming one of the most important dopant species for silicon crystals used in photovoltaics. In this work we have investigated the behavior of indium in silicon crystals grown by the Czochralski pulling process. The experiments were performed by growing 200 mm crystals, which is a standard diameter for large volume production, thus the data reported here are of technological interest for the large scale production of indium doped p-type silicon. The indium segregation coefficient and the evaporation rate from the silicon melt have been calculated to be 5 × 10−4 ± 3% and 1.6 × 10−4 cm·s−1, respectively. In contrast to previous works the indium was introduced in liquid phase and the efficiency was compared with that deduced by other authors, using different methods. In addition, the percentage of electrically active indium at different dopant concentrations is calculated and compared with the carrier concentration at room temperature, measured by four-point bulk method.
Effect of passivation layer grown by atomic layer deposition and sputtering processes on Si quantum dot superlattice to generate high photocurrent for high-efficiency solar cells
Authors: Rahman Mohammad Maksudur , Higo Akio , Sekhar Halubai , Syazwan Mohd Erman , Hoshi Yusuke , Usami Noritaka , Samukawa Seiji 
Published: February 2016

Abstract
The effect of passivation films on a Si quantum dot superlattice (QDSL) was investigated to generate high photocurrent in solar-cell applications. Three types of passivation films, sputter-grown amorphous silicon carbide (a-SiC), hydrogenated a-SiC (a-SiC:H), and atomic-layer-deposited aluminum oxide (ALD-Al2O3), were used to passivate the Si QDSLs containing a stack of four 4 nm Si nanodisks (NDs) and 2 nm silicon carbide (SiC) films fabricated by neutral beam etching (NBE). Because of the high surface-to-volume ratio typically present in quantum Si-NDs formed in the top-down NBE process, there is a tendency to form larger surface dangling bonds on untreated Si-ND surfaces as well as to have short distance (<10 nm) between high-aspect-ratio nanopillars of stacked 4 nm Si-NDs/2 nm SiC films, which conventionally sputter SiC films cannot uniformly cover. Therefore, we optimized the passivation techniques with an ALD-Al2O3 film. Scanning electron microscopy (SEM) analysis helped to explain the surface morphology before and after the passivation of the QDSLs. After the completion of the passivation process, the quality of the top surface films of the QDSLs was analyzed from the surface roughness by atomic force microscopy (AFM) analysis, which revealed that ALD-Al2O3 passivated films had the smallest roughness (RMS) of 1.09 nm with respect to sputter-grown a-SiC (RMS: 1.75 nm) and a-SiC:H (RMS: 1.54 nm) films. Conductive atomic force microscopy (CAFM) revealed that ALD-Al2O3 passivation decreased the surface-leakage current as a result of proper passivation of side-wall surface defects in the QDSLs. The carrier transport characteristics were extracted from the QDSLs using the photovoltaic (PV) properties of p++/i/n+ solar cells, where the QDSLs consisted of different passivation layers acting as intermediate layers (i-layers) between the high-doping-density p++ Si (1 × 1020 cm−3) and n+ Si (1 × 1019 cm−3) substrates. High-doping-density p++ Si acted as a hole conductor instead of a photocarrier generator, hence, we could observe the PV properties of the i-layers. The highest short-circuit current density of 4.75 mA cm−2 was generated from the QDSL with the ALD-Al2O3-passivated surface, which is suitable for high-efficiency QD solar cells compared with a-SiC-passivated (0.04 mA cm−2) and a-SiC:H-passivated (0.37 mA cm−2) QDSL surfaces.