bluuebunny/crossref_metadata_2025_split huggingface dataset:
Un modelo matemático para la bola de fútbol
Authors: Escalante René , Pacheco Francisco 
Published: August 2014

Este trabajo se refiere al análisis, estudio y resolución del problema matemático involucrado en el diseño y construcción de la cobertura de una bola, como las utilizadas en algunos deportes, con miras a lograr una bola con factores óptimos de esfericidad y redondez. El diseño de balones estructuralmente bien distribuidos ha cobrado importancia en los últimos años, sobre todo en el campo de los deportes, como el fútbol. La tendencia actual está dirigida principalmente a la búsqueda de un balón rápido que le de más dinamismo al juego. Para lograr una mayor velocidad del balón en su desplazamiento es importante que éste no sólo tenga una distribución de paneles adecuada, que le de una mayor esfericidad, sino que tenga una estructura que permita una buena distribución de la tensión existente entre los diferentes paneles.
A partir de un diseño inicial, definimos un proceso de reajuste de paneles en la cobertura del balón, que nos conducirá a obtener factores de esfericidad óptimos. Luego, a través de un proceso de “torsión”, logramos agregar área a la superficie sin alterar los factores de esfericidad, resolviendo con ello el problema del faltante de área (i.e., el “Missing Area Problem”, o MAP). Por último, por medio de redefinir la forma final de los paneles, proponemos estrategias de teselado que optimizan la estructura esférica de la bola.
La ecuación de Navier-Stokes y multifractales
Authors: Mercado Escalante José Roberto 
Published: August 2014

No existe, en la actualidad, un teorema general sobre la existencia y la unicidad de las soluciones de la ecuación de Navier-Stokes, la cual describe el flujo de un fluido viscoso e incompresible. Éste es un problema abierto a nivel internacional, llamado el Problema del Premio del Milenio, por el cual el Instituto Clay de Francia está ofreciendo 1 millón de dólares, desde mayo de 2000.
Nuestro propósito, con el presente artículo, es presentar una revisión breve sobre los aspectos más importantes de la evolución y estado actual del problema.
Nuestro aporte es la descripción analítica de la turbulencia, completamente desarrollada, a través de las tasas de la resolución y de los rasgos de procesos multifractal, como una colección de procesos de Cantor generalizados. Presentamos cuatro modelos para la distribución de las variaciones de la velocidad; el primero lo basamos en los tiempos de vida y funciones de riesgo para la interacción entre los vórtices y su posterior fragmentación en vórtices cada vez más pequeños y más numerosos; el segundo, se basa en las pruebas de Bernoulli potenciadas, y encontramos el número de rasgos, el espectro y la función de estructura. Encontramos la relación de los parámetros de forma con la dimensión caja del máximo del espectro; como también, con las dimensiones locales. Y, describimos cuantitativamente el árbol asociado.
Las tasas mencionadas nos sirven de soporte, no sólo, para la descripción de un modelo tridimensional de turbulencia intermitente, que generaliza el resultado paradigmático de Kolmogorov; sino además, la energía transferida en cada etapa del proceso de fractalización; como también, el número de los exponentes característicos, el cual produce una cota superior para la dimensión de Hausdorff del conjunto de singularidades de las soluciones.
El método Statis como alternativa para detectar "response shift" en estudios de calidad de vida relacionada con la salud
Authors: Vicente Galindo María Purificación , Galindo Villardón María Purificación 
Published: August 2014

Evaluar la Calidad de Vida de los pacientes es difícil porque junto al cambio real (alpha) muchos pacientes que experimentan un cambio en su salud (diagnostico de cáncer, por ejemplo), pueden cambiar sus estándar internos de medida (recalibración), sus valores (repriorización), o incluso reconceptualizar lo que antes entendían por Calidad de Vida (Cambios Beta y Gamma). Este fenómeno es conocido como “Response Shift” y justifica la paradoja descrita en la literatura por la cual pacientes con graves problemas de salud perciben una Calidad de Vida más alta de la estimada por médicos y familiares.
En este trabajo, después de evaluar los problemas existentes a la hora de definir el constructo Calidad de Vida, centramos la atención en las dimensiones del Response Shift. Se discuten las limitaciones del método clásico de Ahmavaara y se proponen soluciones para detectar y evaluar las componentes Beta y Gamma del Response Shift.
Portfolio Optimization Using Particle Swarms with Stripes
Authors: Villalobos-Arias Mario 
Published: August 2014

In this paper it is consider the Portfolio Optimization Problem developed by Markowitz [11]. The basic assumption is that the investor tries to maximize his/her profit and at the same time, wants to minimize the risk. This problem is usually solved using a scalarization approach (with one objective). Here it is solved it as a bi-objective optimization problem. It uses a new version of the algorithm of Particle Swarm Optimization for Multi-Objective Problems to which it implemented a method of the stripes to improve dispersion.
Circular chains of chinese dice
Authors: Piza Eduardo , Schubert Leo 
Published: August 2014

In this paper we study Chinese dice, mathematical objects similar to ordinary dice but allowing repetition among their face values. We say that a die A is preferred over a die B (written A > B) if A wins more frequently than B does. We study first the existence of circular chains of three dice A, B, C (those that A > B > C > A) using a mixed integer programming algorithm. Then we generalize the problem to n-dimensional dice—that is, dice of n faces, with n ≥ 4—and we search circular chains of length m (with m ≥ 3) using a simulated annealing algorithm. We compare some different objective functions and obtain good solutions to the problem with very efficient algorithms. Finally we obtain a theoretical result concerning the existence of circular chains in the general case.
Sobre una construcción de un monoide libre con identidad sobre un topos E con el objeto de los números naturales
Authors: Acuña Ortega Osvaldo 
Published: August 2014

Damos una construcción del monoide libre con identidad sobre un objeto X, M(X). Donde
M(X) = {R ∈ ΩN×N×X/R es funcional y ∃n∈N dom R = [n]} −−iX→ ΩN×N×X .
El espacio cociente y algunas propiedades geométricas de los espacios de Banach
Authors: Morales Jose R. 
Published: August 2014

En esta nota enunciaremos alguans propiedades geométricas de los espacios de Banach, entre las cuales podemos señalar espacios uniformemente convexos, espacios uniformemente no cuadrados, espacios localmente uniformemente convexos, espacios estrictamente convexos, etc., y analizaremos el problema cuando tales propiedades se trasladan al espacio cociente.
Lemniscatas 3D
Authors: Ortega Rafael , Paluszny Marco 
Published: August 2014

Una lemniscata 3D es una superficie que consiste en los puntos cuyo producto de distancias a un conjunto (finito) de puntos fijos ó focos es constante. En este trabajo se introducen las lemniscatas 3D en el contexto de la modelación geométrica, se explora en particular, el caso de tres focos, especialmente en lo relativo a la deformación controlada.
Modelling Development of a Thermal Gas/Oil Gravity-Drainage Process in an Extraheavy-Oil Fractured Reservoir
Authors: Niz-Velasquez Eider , Bagheri S. R. , van Dorp Johan J. , Verlaan Marco L. , Jennings James W. 
Published: August 2014

Summary
Thermal gas/oil gravity drainage (T-GOGD) is an attractive enhanced-oil-recovery method applicable to naturally fractured reservoirs (NFRs). The process is applied successfully in Qarn Alam, a heavy-oil field in Oman. This paper presents a case study featuring dynamic-modelling optimization and uncertainty-analysis workflow for T-GOGD in a bitumen-bearing fractured reservoir on the basis of realistic 3D fracture characterization. In T-GOGD, the fractures are displaced to steam to provide a (matrix) gravity-drainage potential while heating the reservoir at the same time. One of the recovery mechanisms associated with T-GOGD is thermal expansion, which can result in high initial rates, but may cause plugging of the fracture system in the case of extraheavy oil (bitumen) if the expanded oil cools down before it is being produced. This situation requires short-distance well configurations and/or steam-stimulation cycles to establish communication. In an NFR, steam vapour occupies the fracture system while oil drains through the matrix, increasing the area for heat transfer with respect to the steam-chamber case; the process therefore differs significantly from steam-assisted gravity drainage, and a different production function applies. Shell’s in-house reservoir simulator MoReS with advanced dual-permeability capability is used to model development of T-GOGD in a bitumen reservoir employing 3D element-of-symmetry (EOS) models. A realistic fracture-characterization and -modelling process is described. The geometrical well configuration and operating schedule and strategy are optimized on an economic function for a deterministic subsurface realization. Using an uncertainty-analysis work flow, cumulative distribution functions of recovery and steam/oil ratio (SOR) are generated. Finally, robust optimization is explored by use of an economic objective function. The study concludes that (1) relatively large well spacing is feasible while injector/producer horizontal well offset is necessary to avoid steam channeling to the producer well, (2) live steamproduction control is a robust operating strategy, (3) performance is most sensitive to matrix permeability and oil viscosity, and (4) vertical fracture connectivity plays an important role in the process performance. T-GOGD has significant potential to develop the bitumen resource in naturally fractured carbonates.
Enhanced Biodegradability of Pharmaceuticals and Personal Care Products by Ionizing Radiation
Authors: Kim Hyun Young , Lee O‐Mi , Kim Tae‐Hun , Yu Seungho 
Published: August 2014

ABSTRACT: The radiolytic degradation of antibiotic compounds, including lincomycin (LMC), sulfamethoxazole (SMX), and tetracycline (TCN), and the change of biodegradability of the radiation‐treated target compounds were evaluated. As a result, the degradation of target antibiotics by hydrolysis, biodegradation, and gamma irradiation showed a compound‐dependent manner. However, the biodegradability of all target compounds was enhanced by the gamma irradiation. The enhanced biodegradability after gamma irradiation (2 kGy) followed the trend of LMC (18.89%) < SMX (28.33%) < TCN (36.62%), indicating that gamma irradiation might transform nonbiodegradable compounds into biodegradable. Consequently, the effective degradation of nonbiodegradable antibiotics can be accomplished by ionizing radiation followed by biodegradation. This result indicated that ionizing radiation technology would be useful to enhance biodegradability of the recalcitrant pollutants and can facilitate further degradation of residuals or intermediates in the effluent when discharged into surface water.
The Effect of Seed Health of Perennial Ryegrass (Lolium Perenne L.) on Germination Capacity
Authors: Wiewióra Barbara 
Published: August 2014

Abstract
The analysis of seed health and germination capacity of 7 varieties of Lolium perenne, originated from two breeding station and two seed company localized in different places of Poland, harvested in 2006, 2007 and 2008 were performed. Results of mentioned analysis indicated that seeds were contaminated by numerous species of fungi. The most numerous group of fungi were saprophytes or weak parasites such as: Alternaria alternata, Epicoccum nigrum, Septonema chaetospira and Penicillium spp. Pathogenic species were represented by species of Drechslera, Fusarium, Phoma, Curvularia lunata and Bipolaris sorokiniana. Seed germination capacity was influenced by contamination of fungi. It was found that seed more often contaminated by fungi germinated much poorer then seed with lower infection.
The Safety and Efficacy of Chloral Hydrate Sedation for Pediatric Ophthalmic Procedures: A Retrospective Review
Authors: Wilson Michelle E. , Karaoui Mohammed , Djasim Leyla Al , Edward Deepak P. , Shamrani Mohammad Al , Friedman David S. 
Published: August 2014

Purpose:
To determine the safety and efficacy of high-dose oral chloral hydrate for pediatric ophthalmic procedures.

Methods:
This study is a retrospective review of a quality audit of pediatric sedation for ophthalmic evaluation and imaging performed at King Khaled Eye Specialist Hospital between January 1 and December 31, 2011, in children aged 1 month to 6 years.

Results:
Three hundred fifty-eight of 380 (94.2%) sedation procedures were successful after a single dose of chloral hydrate, with 356 of 380 (93.7%) children sedated within 45 minutes of the first dose. The total success rate of the sedation procedure increased to 97.9% (372 of 380) when a second dose was administered. Children adequately sedated after a single dose of chloral hydrate were on average younger and weighed less than children who required additional doses. No major adverse events were documented.

Conclusions:
The use of chloral hydrate sedation for ophthalmic evaluation and imaging was safe and effective in this patient population with a high rate of procedure completion.

[J Pediatr Ophthalmol Strabismus 2014;51(3):154–159.]
Medium-Term Outcomes of Three Horizontal Muscle Surgery in Large-Angle Infantile Esotropia
Authors: Bayramlar Hüseyin , Karadag Remzi , Yildirim Aydin , Öçal Ayse , Sari Ünsal , Dag Yasar 
Published: August 2014

Purpose:
To evaluate the medium-term motor outcomes of three horizontal muscle surgery in patients with large-angle infantile esotropia.

Methods:
The charts of 18 patients with large-angle (> 55 prism diopters [PD]) infantile esotropia who underwent bilateral medial rectus muscle recession and one lateral rectus muscle resection were retrospectively reviewed. Preoperative and postoperative deviations at last examination, overcorrections and undercorrections, necessity of additional horizontal surgery, and follow-up durations were recorded.

Results:

The median age of patients at surgery was 22 months (range: 10 to 168 months). Orthotropia to within 10 PD or less was achieved in 14 of 18 patients (78%) in a median follow-up of 32 months (range: 5 to 63 months). The mean preoperative deviation of 68.8 ± 9.54 PD decreased to a median of 1 PD (range: esotropia 30 to exophoria 4 PD) postoperatively (
P
< .005). Marked residual esotropia necessitating additional surgery occurred in 4 patients, but significant overcorrection was not observed.

Conclusions:
The success rate of the three horizontal muscle surgeries appears to be high enough in medium-term follow-up in patients with large-angle infantile esotropia. Overcorrection that necessitates additional horizontal muscle surgery does not seem to be significant in the medium term, according to this study.

[J Pediatr Ophthalmol Strabismus 2014;51(3):160–164.]
Propranolol and Periocular Capillary Hemangiomas: Assessment of Refractive Effect
Authors: Glasman Peter , Chandna Arvind , Nayak Harish , Mangat Simran , Kaye Stephen 
Published: August 2014

Purpose:
To assess the effects of systemic propranolol on refractive error in infants with periocular capillary hemangiomas.

Methods:
A single-center study of consecutive patients with capillary hemangiomas treated with systemic propranolol. Refractive data were analyzed using Long’s matrix formalism and the methods of Harris and Kaye.

Results:

Seventeen patients were included. At 6 months postoperatively, hemangioma size reduced from 3,214 to 1,806 mm
3
(standard deviation: 4,122 to 2,441). Mean refractive error in the affected eye significantly reduced: −1.25/0.38 × 36 (95% confidence intervals: −5.08/1.20 × 90 to 1.64/1.43 × 180,
P
= .048) with a smaller change (
P
= .06) in the unaffected eye of −1.01/+0.31 × 3.16 (95% confidence intervals: −4.02/+1.12 × 180 to +1.49/+0.51 × 90).

Conclusions:
Propranolol produced a clinically significant reduction in the infants’ refractive error and anisometropia. The reduction in the total refractive error and anisometropia has not been evident in previous analyses, which have concentrated on the change in the “cylinder” as the principal outcome measure.

[J Pediatr Ophthalmol Strabismus 2014;51(3):165–170.]
Comparison of Surgically Induced Astigmatism Following Iris-Claw PIOL Insertion With Scleral, Limbal, or Corneal Incisions
Authors: Kwon Hee Jung , Nam Sang Min , Stulting R. Doyle , Lim Chan Young , Seo Kyoung Yul 
Published: August 2014

PURPOSE:
To compare surgically induced astigmatism (SIA) based on incision site and evaluate the clinical results and astigmatic stability of iris-claw phakic intraocular lens (Artisan lens; Ophtec BV, Groningen, Netherlands) implantation.

METHODS:
Eighty-five eyes of 53 patients with myopia who underwent Artisan lens implantation with a 6.2-mm incision and follow-up of 6 months were retrospectively observed. SIA was assessed using keratometric astigmatism at 6 months postoperatively for the incision sites of the sclera, limbus, and cornea, and the efficacy, safety, predictability, and astigmatic stability were also calculated.

RESULTS:

SIA obtained using Naeser’s polar method (KP[90]
SIA
) was −0.48 ± 0.35 for scleral incisions, −0.99 ± 0.35 for limbal incisions, and −1.14 ± 0.54 for corneal incisions. Corresponding net astigmatism values, as calculated with KP(90)
SIA
and KP(135)
SIA
, were 0.70 ± 0.48 (177°), 1.04 ± 0.37 (175°), and 1.21 ± 0.57 (1°), respectively, with SIA increasing the nearer the incision was to the cornea center. Six months after surgery, the efficacy index was 1.03 and the safety index was 1.08. Ninety-eight percent of patients were within 1.50 diopters of attempted refraction.

CONCLUSIONS:
The values of SIA after Artisan lens insertion showed significant differences among three incision locations, despite the absence of significant differences in preoperative steep corneal axis astigmatism values at the incision locations. It would be applicable for refractive surgery in the aspect of minimizing astigmatism after surgery.

[
J Refract Surg.
2014;30(5):330–335.]
GPR for the inspection of industrial railway tracks
Authors: Hugenschmidt Johannes , Kasa Carl , Kato Hiroyuki 
Published: August 2014

ABSTRACTIndustrial railway tracks are important for the loading and unloading of goods and therefore for the railway system in general. Often, industrial tracks are embedded in concrete and/or asphalt to enable trucks and other traffic across rails. Thus, most of the construction is hidden from visual inspection. If repair work is planned or if damage occurs, details of the construction have to be known for the planning of repair work and for the evaluation of damages. This paper describes the characteristics of industrial railway tracks, frequent problems and the non‐destructive testing on several real sites using GPR. Typical testing problems, most of them related to construction details, are described and the application of GPR for these problems is demonstrated using data from field measurements. Data from different types of equipment are compared and benefits and limits of the method are discussed. It is shown that GPR can provide information that is required to address problems that can be found frequently on industrial railway track sites.
A comprehensive study of parameter determination in a joint MRS and TEM data analysis scheme
Authors: Behroozmand Ahmad A. , Dalgaard Esben , Christiansen Anders Vest , Auken Esben 
Published: August 2014

ABSTRACTWe present a comprehensive study of the parameter determination of magnetic resonance sounding (MRS) models in a joint MRS and transient electromagnetic (TEM) data analysis scheme. The parameter determination is assessed by calculating the model parameter uncertainties based on an a posteriori model covariance matrix. An entire MRS data set, dependent on pulse moment and time gate values, together with TEM data, is used for all analyses and realistic noise levels are assigned to the data.Sensitivity analyses are studied for the determination of water content as a key parameter estimated during inversion of MRS data. We show the results for different suites of (three‐layer) models, in which we investigate the effect of resistivity, water content, relaxation time, loop side length, number of pulse moments and measurement dead time on the determination of water content in a water‐bearing layer. For all suites of models the effect of a top conductive and a top resistive layer are compared. Moreover, we analyse all models for a long (40 ms) and short (10 ms) measurement dead time. The effect of noise level on the parameter determination is also analysed.We conclude that, in general, the resistivity of the water‐bearing layer (layer of interest, LOI) does not affect the determination of water content in the LOI but the resistivity of the top layer increases depth resolution; the water content of the LOI does not influence its determination considerably in cases where the signal has a relatively long relaxation time in the LOI; determination of the water content in the LOI is improved by increasing the relaxation time of the signal in the LOI; short measurement dead time will improve the parameter determination for signals with a relatively short relaxation time; increasing loop side length and the number of pulse moments do not necessarily improve the parameter determination.
Faulting and groundwater in a desert environment: constraining hydrogeology using time‐domain electromagnetic data
Authors: Bedrosian Paul A. , Burgess Matthew K. , Nishikawa Tracy 
Published: August 2014

ABSTRACTWithin the south‐western Mojave Desert, the Joshua Basin Water District is considering applying imported water into infiltration ponds in the Joshua Tree groundwater sub‐basin in an attempt to artificially recharge the underlying aquifer. Scarce subsurface hydrogeological data are available near the proposed recharge site; therefore, time‐domain electromagnetic (TDEM) data were collected and analysed to characterize the subsurface. TDEM soundings were acquired to estimate the depth to water on either side of the Pinto Mountain Fault, a major east‐west trending strike‐slip fault that transects the proposed recharge site. While TDEM is a standard technique for groundwater investigations, special care must be taken when acquiring and interpreting TDEM data in a two‐dimensional (2D) faulted environment. A subset of the TDEM data consistent with a layered‐earth interpretation was identified through a combination of three‐dimensional (3D) forward modelling and diffusion time‐distance estimates. Inverse modelling indicates an offset in water table elevation of nearly 40 m across the fault. These findings imply that the fault acts as a low‐permeability barrier to groundwater flow in the vicinity of the proposed recharge site. Existing production wells on the south side of the fault, together with a thick unsaturated zone and permeable near‐surface deposits, suggest the southern half of the study area is suitable for artificial recharge. These results illustrate the effectiveness of targeted TDEM in support of hydrological studies in a heavily faulted desert environment where data are scarce and the cost of obtaining these data by conventional drilling techniques is prohibitive.