Nuevo conocimiento - i2T

URI permanente para esta colecciónhttp://hdl.handle.net/10906/78226

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El compromiso de continuidad y el vínculo del consumidor con la organización
(Pontificia Universidad Javeriana, 2016-01-01) Arboleda Arango, Ana Maria
This article evaluates the extent to which a consumer's continuance commitment to an organization moderates the relationship between his affective commitment and behavioral intention. The continuance commitment is operationalized in two ways: the possibility a consumer has to choose a healthcare organization and the cost of switching from an education institution by having a scholarship. Results show that the affective commitment increases behavioral intentions towards the organization. This relationship decreases when the continuance commitment relates with the cost and the possibility of choosing the service provider. Future studies could replicate this methodology for cases dealing with brands or massive consumption products and, on another side, could confirm the emotional experience of those consumers who receive additional benefits.
Utilizando herramientas de simulación para análisis de parámetros de c alidad de servicio en rede s NGN
(CINTEL Centro de Investigación de las Comunicaciones, 2010-04-01) Cuéllar Quiñones, Juan Carlos
Para el análisis y diseño de redes, los ingenieros siempre han contado con herramientas de simulación que les permiten recrear de una manera aproximada situaciones que se pueden presentar en este tipo de entornos. Y con los resultados obtenidos, después de su análisis, se pueden tomar decisiones con respecto al diseño o implementación de algún tipo de solución.
Visual palatability of food dishes in color appearance, glossiness and convexo-concave perception depending on light source
(The Illuminating Engineering Institute of Japan, 2015-01-01) Okajima, Katsunori
This study aims to reveal visual factors which determine the visual palatability of food dishes. We conducted subjective experiments under different light sources, and examined the correlation between the visual palatability and the visual factors, color appearance, glossiness, and convexo-concave perception. We prepared twelve kinds of food dishes, and measured the chromaticity values of all dishes under six kinds of light sources. Next, we transformed the measured data into their respective RGB values. This color management process ensures that the digital images can be displayed with the same chromaticity values as the real objects so that participants can observe the same visual stimuli with no olfactory cues. Twenty participants observed one of the images for one minute, and evaluated the "visual palatability", and answered subjectively three factors, "color appearance", "glossiness" and "convexo-concave perception". As a result, it was revealed that higher correlated color temperature light makes the dishes more palatable, suggesting that the color appearance is an important visual factor for the visual palatability of food dishes. In addition, it was shown that the visual palatability of the raw food dishes and the dishes with sauce can be affected by both color appearance and glossiness depending on the light source.
Spectrum monitoring low-cost system for developing countries
(International Telecommunications Union, 2013-01-01) Vargas Bernal, Leonardo
[No hay resumen disponible]
Runtime Evolution of Highly Dynamic Software
(Springer,, 2014-01-01) Villegas Machado, Norha Milena
Highly dynamic software systems are applications whose operations are particularly affected by changing requirements and uncertainty in their execution environments. Ideally such systems must evolve while they execute. To achieve this, highly dynamic software systems must be instrumented with self-adaptation mechanisms to monitor selected requirements and environment conditions to assess the need for evolution, plan desired changes, as well as validate and verify the resulting system. This chapter introduces fundamental concepts, methods, and techniques gleaned from self-adaptive systems engineering, as well as discusses their application to runtime evolution and their relationship with off-line software evolution theories. To illustrate the presented concepts,
Implementación de OpenFlow sobre NetFPGA
(Universidad Surcolombiana, 2014-04-30) Ramos, Andrés Felipe
Las redes tradicionales están diseñadas e implementadas con diferentes dispositivos de red, como routers, switches y firewalls; cada uno tiene unas funciones asociadas y es configurado con diferentes estándares y protocolos para realizar la trasmisión de paquetes. Pero este modelo tradicional no es el único que existe, hoy en día se está empezando a imponer un nuevo modelo de red definida por software [SDN por Software Define Networks]. Si bien este modelo usa los mismos dispositivos de red, es diferente pues utiliza las ventajas del software de programación, el cual mediante una inter- faz universal controla los dispositivos de red y programa los servicios de envío o enrutamiento de paquetes. Este artículo presenta las ventajas de las SDN respecto de las redes tradicionales y muestra pruebas de desempeño básicas realizadas en un ambiente de laboratorio con una tarjeta NetFPGA implementando OpenFlow, en contraste con pruebas de desempeño realizadas con dispositivos de red comerciales.
Image statistics on the age perception of human skin
(Wiley, 2013-02-01) Arce Lopera, Carlos Alberto
Recent research on the age-dependent changes of facial skin has analyzed their correlation with changes in image and colorimetric properties using mainly first- and second-order statistics. The aim of this study is to reveal the importance of third-order statistics and relate those image properties to skin age perception.
Effects of diffuse and specular reflections on the perceived age of facial skin
(Springer Verlag, 2012-05-01) Arce Lopera, Carlos Alberto
Age perception is a better biomarker of skin aging than chronological age. However, the optical cues that determine the perception of human skin age are difficult to assess given the complex interactions between light and the multi layered structure of the skin. The aim of the present study is to clarify the independent contribution of both diffuse and specular reflection components to the skin age perception
Combining spectral and fractal features for emotion recognition on Electroencephalographic signals
(World Scientific and Engineering Academy and Society, 2014-01-01) Ulloa Villegas, Gonzalo Vicente
Recent studies have attempted to recognize emotions by extracting spectral and fractal features from electroencephalographic signals; however, up to now none of them have combined these two features to recognize emotions. This paper aims at providing a comparison between an accuracy rate of an approach that recognizes emotions by extracting both spectral and fractal features with that of those that extract only one of these features. To this end, we designed and implemented a procedure that recognizes positive and negative emotions by extracting spectral, fractal, or both features. Next, using this procedure, we built three different approaches to recognize positive and negative emotions; the first one extracted both spectral and fractal features, whereas the other two extracted each type of feature separately.
A Comparison of Taxonomies for Model Transformation Languages
(Universidad de los Andes, 2010-01-01) Tamura Morimitsu, Gabriel
Since the introduction of the MDE/MDA/MDD ideas for software systems development several years ago, a number of different (meta)modeling and model transformation languages have been proposed. Although the OMG's QVT standard specification has somewhat stabilized the number of new model transformation languages, it is likely that new ones will continue to appear, following different paradigms and approaches. However, the evolution towards the consolidation of models as a unifying, foundational and consistent concept for software-intensive system development, requires the realization of a set of ideal characteristics for the specification of model transformation languages. Several works have been proposed for defining characterization and classification schemes, and the set of these ideal characteristics.
WLAN's access points java based automatic location tool
(World Wireless Congress, 2007-05-23) Navarro Cadavid, Andrés
In this paper, we will show the development process and the results obtained with a Java based toll for automatic location of WLAN Access Points. We will describe the algorithm developed and the results obtained until the time we wrote the paper. Also we will discuss future work and possible evolution for the tool.
Identifying competitive interaction of patterns in software product lines
(Universidad de Santiago de Cali, Facultad de Ingeniería, Facultad de Ciencias Básicas, 2015-07-01) Arboleda, Hugo
Los patrones de diseño para empresas (tales como los patrones JEE) pueden ser usados para promover Atributos de Calidad [Quality Attributes, QA] como funcionalidades cuando se derivan en una línea de productos software [Software Product Line, SPL]. Uno de los aspectos encontrados en la derivación de productos es la interacción de fragmentos de código generados por la aplicación de patrones. Esta interacción puede ser colaborativa o de competitiva. Cuando es competitiva, las relaciones pueden ser adaptables o excluyentes. En ambos casos, los diferentes enfoques (e.g., la composición patrón, el patrón de sustitución, el razonamiento de restricción) se pueden usar para abordar el problema. Sin embargo, la identificación y predicción temprana de estas interacciones puede ser útil para desarrollar estrategias adecuadas. Este trabajo explora e identifica las interacciones usando dos repositorios base: QAs de un reconocido estándar y patrones de un catálogo. Se muestran dos casos de interacción funcional, cuando se promueven niveles específicos de QA en una aplicación empresarial [SPL].
Ajuste estadístico de modelos de propagación de señal usando medidas de la ciudad de Cali
(Universidad de Santiago de Cali,, 2012-03-20) Ardila, Carlos Andredy
La dificultad de estimar con exactitud la influencia de los obstáculos, los edificios y el terreno en la pérdida de trayectoria de la señal hace que los modelos de propagación, generalmente utilizados para la planificación de redes inalámbricas externas, en entornos urbanos incluyan algunos elementos empíricos. Por lo tanto, la ecuación final generalmente contiene constantes y coeficientes para los diferentes términos, que se obtienen principalmente a partir del análisis estadístico de mediciones recolectadas durante actividades de drive test en grandes áreas de la ciudad. Desafortunadamente, estos resultados son realmente válidos únicamente para las áreas de la ciudad en las que se obtuvieron y, en el mejor de los casos, para áreas o ciudades similares. Sin embargo, si el nivel de similitud no es suficiente, es necesario realizar ajustes, un proceso que resulta en la formulación de nuevas constantes y nuevos coeficientes. El propósito de este artículo es discutir algunos de los hallazgos obtenidos durante el proceso de ajuste estadístico al escenario de la ciudad de Cali, de los modelos Okumura-Hata, Stanford University Interim (SUI) y Walfisch-Bertoni, usando mediciones.
Development and instrumentation of a framework for the generation and management of self-adaptive enterprise applications
(Pontificia Universidad Javeriana, 2016-01-01) Jiménez, Miguel Angel
Companies’ operations have become over-dependent on their supporting enterprise software applications. This situation has placed a heavy burden onto software maintenance teams who are expected to keep these applications up and running optimally in varying execution conditions. However, this high human intervention drives up the overall costs of software ownership. In addition, the current dynamic nature of enterprise applications constitutes challenges with respect to their architectural design and development, and the guarantee of the agreed quality requirements at runtime. Efficiently and effectively achieving the adaptation of enterprise applications requires an autonomic solution. In this paper, we present SHIFT, a framework that provides (i) facilities and mechanisms for managing self-adaptive enterprise applications using an autonomic infrastructure, and (ii) automated derivation of self-adaptive enterprise applications and their respective monitoring infrastructure. Along with the framework, our work led us to propose a reference specification and architectural design for implementing self-adaptation autonomic infrastructures. We developed a reference implementation of SHIFT; our contribution includes the development of monitoring infrastructures, and dynamic adaptation planning and automated derivation strategies. SHIFT, along with its autonomic infrastructure and derived enterprise application, can provide a cost-effective mean to fulfill the agreed quality in these types of applications. © 2016, Pontificia Universidad Javeriana. All rights reserved.
Desarrollo e Instrumentación de un Proceso de Vigilancia Tecnológica basado en Protocolos de Revisión Sistemática de la Literatura
(Centro de Información Tecnológica, 2016-01-01) Méndez, Diego
This paper presents a technology surveillance process that takes into account activities associated with the process of conducting systematic literature reviews. Technology surveillance is a part of the research and innovation management system in industrial contexts. The aim of the proposal is to provide access, management and contextualization of scientific and technical knowledge to be at the forefront of technologies for supporting business strategy. Systematic literature reviews consider a detailed process to study the state of the art in a particular field of knowledge. This type of reviews constitutes a facilitator of effective technology surveillance processes. The innovative nature of the process is two-fold. On the one hand, integrates best practices to carry out technology forecasting and systematic literature reviews and on the other, a support tool (LOXO) is proposed for the execution of technology surveillance processes.
Design and simulation of a collision notification application with geocast routing for car-to-car communications
(Springer Verlag, 2015-12-01) Orozco, Ana María
Introduction: Car-to-X Communications are envisioned to improve road safety, traffic efficiency, and information services through short-range and real-time systems. The enabling applications have varied requirements such as low latency, specific forwarding patterns, and reliable data exchange between vehicles and infrastructure. Hence, a cross-layer architecture for vehicular applications should be defined according to the goals of the implementation, so as to consider proper routing and dissemination mechanisms, communication protocols, and the application’s design and operation. Methods: In this context, we propose the characterization of the upper layers of a safety-oriented Car-to-Car application.
Delay spread estimation using a Game Engine Ray based model in indoor scenario at 5 GHz
(Asian Research Publishing Network, 2016-03-01) Gimenez, Jordi Joan
In this paper we show the results of a simulation of channel parameters using a Game Engine Ray based tool, developed by our group, which has been evolving during last few years. We show simulation results and compare it with a set of measurements for an indoor scenario, in the band of 5.4 GHz. We found a good match between the rays based tool and measurements for Delay Spread. Also, we show the use of an Open Source 3D modelling tool for the scenario building, showing the flexibility of the XML description language for this kind of scenarios. © 2006-2016 Asian Research Publishing Network (ARPN).
Delay spread estimation in 4,2GHz band using game ray based method
(Institute of Electrical and Electronics Engineers Inc., 2016-10-27) Guevara, Daniel
The evolution of mobile systems has leaded to new frequency attributions like 3,5 to 4,2 GHz band. In this paper, we show the channel behavior of 4,2GHz in indoor scenario using a ray based system and compare delay spread results with measurements. We try to tune our model, adjusting permittivity values to reduce the mean standard error and analyze the effect of the permittivity differences in the scenario. © 2016 IEEE.
Availability of TV White Spaces Using Spectrum Occupancy Information and Coverage Maps
(IEEE Computer Society, 2016-06-01) Navarro Cadavid, Andrés
Radio Spectrum is the natural resource that allows the operation of radio services, such as Television, Mobile Telephony, and applications for Intelligent Transportation Services, Internet of Things, among others. The current allocation system is inefficient because assigned spectrum is not fully utilized by operators and cannot be accessed by any other user, despite its availability. Secondary spectrum usage is proposed as an alternative to optimize its use, allowing that a secondary user can access certain portion of spectrum allocated to primary service. In particular of TV service, this portion is known as TV White Space, TVWS. The most common models to identify available spectrum in TV service are based on frequency allocation and network planning information provided by TV operators, which are not enough to make an accurate estimation. A spectrum detection model built with traditional models and analysis of coverage maps obtained by simulations is presented, and applied in Cali Colombia to establish how many TVWS are available, taking into account the effect that terrain has on the propagation of the service. The amount of TVWS detected increases using our model compared to TVWS identified only with traditional models. © 2016 IEEE.
A Model to Guide Dynamic Adaptation Planning in Self-Adaptive Systems
(Elsevier, 2016-03-14) Arboleda Jiménez, Hugo Fernando
Self-adaptive enterprise applications have the ability to continuously reconfigure themselves according to changes in their execution contexts or user requirements. The infrastructure managing such systems is based on IBM's MAPE-K reference model: a Monitor and an Analyzer to sense and interpret context data, a Planner and an Executor to create and apply structural adaptation plans, and a Knowledge manager to share relevant information. In this paper we present a formal model, built on the principles of constraint satisfaction, to address dynamic adaptation planning for self-adaptive enterprise applications. We formalize, modify and extend the approach presented in [H. Arboleda, J. F. Díaz, V. Vargas, and J.-C. Royer, "Automated reasoning for derivation of modeldriven spls," in SPLC'10 MAPLE'10, 2010, pp. 181-188] for working with self-adaptation infrastructures in order to provide automated reasoning on the dynamic creation of structural adaptation plans. We use a running example to demonstrate the applicability of such model, even in situations where complex interactions arise between context elements and the target self-adaptive enterprise application.

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