Showing papers by "Open University of Catalonia published in 2011"

The World’s Technological Capacity to Store, Communicate, and Compute Information

Abstract: We estimated the world’s technological capacity to store, communicate, and compute information, tracking 60 analog and digital technologies during the period from 1986 to 2007. In 2007, humankind was able to store 2.9 × 10 20 optimally compressed bytes, communicate almost 2 × 10 21 bytes, and carry out 6.4 × 10 18 instructions per second on general-purpose computers. General-purpose computing capacity grew at an annual rate of 58%. The world’s capacity for bidirectional telecommunication grew at 28% per year, closely followed by the increase in globally stored information (23%). Humankind’s capacity for unidirectional information diffusion through broadcasting channels has experienced comparatively modest annual growth (6%). Telecommunication has been dominated by digital technologies since 1990 (99.9% in digital format in 2007), and the majority of our technological memory has been in digital format since the early 2000s (94% digital in 2007).

Mediterranean diet pyramid today. Science and cultural updates

Abstract: Objective To present the Mediterranean diet (MD) pyramid: a lifestyle for today. Design A new graphic representation has been conceived as a simplified main frame to be adapted to the different nutritional and socio-economic contexts of the Mediterranean region. This review gathers updated recommendations considering the lifestyle, dietary, sociocultural, environmental and health challenges that the current Mediterranean populations are facing. Setting and Subjects Mediterranean region and its populations. Results Many innovations have arisen since previous graphical representations of the MD. First, the concept of composition of the ‘main meals’ is introduced to reinforce the plant-based core of the dietary pattern. Second, frugality and moderation is emphasised because of the major public health challenge of obesity. Third, qualitative cultural and lifestyle elements are taken into account, such as conviviality, culinary activities, physical activity and adequate rest, along with proportion and frequency recommendations of food consumption. These innovations are made without omitting other items associated with the production, selection, processing and consumption of foods, such as seasonality, biodiversity, and traditional, local and eco-friendly products. Conclusions Adopting a healthy lifestyle and preserving cultural elements should be considered in order to acquire all the benefits from the MD and preserve this cultural heritage. Considering the acknowledgment of the MD as an Intangible Cultural Heritage of Humanity by UNESCO (2010), and taking into account its contribution to health and general well-being, we hope to contribute to a much better adherence to this healthy dietary pattern and its way of life with this new graphic representation.

Ethnography goes online: towards a user-centred methodology to research interpersonal communication on the internet:

Abstract: Ethnographic research is increasingly concerned with how the internet operates within our everyday life. This article attempts to offer a methodological contribution of online communication and an exploration of initial empirical data generated with this methodology. The article calls for a specification of how ethnography can be applied appropriately to the study of relationships online. It departs from the real versus virtual dichotomy, offering a user-centred methodology to study interpersonal communications on the internet. It suggests the use of three main strategies to pay tribute to the characteristics of uses online: multi-situated, online and offline, and flexible and multimedia data collection methods. This approach facilitates a holistic analysis of the way in which social information and communication technologies operate within society in everyday life. It deals with the problem of defining the setting of research online and proposes an expanded ethnography. The article specifies details of this methodology for research into interpersonal communications and emotions online. It does so by drawing on empirical data generated in a study on everyday life and emotions on the internet. Epistemic questions related to this methodological approach will also be discussed. Overall, the exemplification suggests that the methodological approach proposed here is able to capture the uses and understandings of the internet.

On the use of Monte Carlo simulation, cache and splitting techniques to improve the Clarke and Wright savings heuristics

Abstract: This paper presents the SR-GCWS-CS probabilistic algorithm that combines Monte Carlo simulation with splitting techniques and the Clarke and Wright savings heuristic to find competitive quasi-optimal solutions to the Capacitated Vehicle Routing Problem (CVRP) in reasonable response times. The algorithm, which does not require complex fine-tuning processes, can be used as an alternative to other metaheuristics—such as Simulated Annealing, Tabu Search, Genetic Algorithms, Ant Colony Optimization or GRASP, which might be more difficult to implement and which might require non-trivial fine-tuning processes—when solving CVRP instances. As discussed in the paper, the probabilistic approach presented here aims to provide a relatively simple and yet flexible algorithm which benefits from: (a) the use of the geometric distribution to guide the random search process, and (b) efficient cache and splitting techniques that contribute to significantly reduce computational times. The algorithm is validated through a set of CVRP standard benchmarks and competitive results are obtained in all tested cases. Future work regarding the use of parallel programming to efficiently solve large-scale CVRP instances is discussed. Finally, it is important to notice that some of the principles of the approach presented here might serve as a base to develop similar algorithms for other routing and scheduling combinatorial problems.

Using safety stocks and simulation to solve the vehicle routing problem with stochastic demands

Abstract: After introducing the Vehicle Routing Problem with Stochastic Demands (VRPSD) and some related work, this paper proposes a flexible solution methodology. The logic behind this methodology is to transform the issue of solving a given VRPSD instance into an issue of solving a small set of Capacitated Vehicle Routing Problem (CVRP) instances. Thus, our approach takes advantage of the fact that extremely efficient metaheuristics for the CVRP already exists. The CVRP instances are obtained from the original VRPSD instance by assigning different values to the level of safety stocks that routed vehicles must employ to deal with unexpected demands. The methodology also makes use of Monte Carlo simulation (MCS) to obtain estimates of the reliability of each aprioristic solution – that is, the probability that no vehicle runs out of load before completing its delivering route – as well as for the expected costs associated with corrective routing actions (recourse actions) after a vehicle runs out of load before completing its route. This way, estimates for expected total costs of different routing alternatives are obtained. Finally, an extensive numerical experiment is included in the paper with the purpose of analyzing the efficiency of the described methodology under different uncertainty scenarios.

E-Learning: Confusing Terminology, Research Gaps and Inherent Challenges

Abstract: This article examines the problem of defining a broad conceptual theory for the applications of the advanced technologies in educational settings, most particularly in higher education. The article starts with discussing the multiple and confusing meanings of e-learning in the relevant literature; it proceeds to examine the problem of putting the learners in the center of the study process and exaggerating their self-directed abilities; it identifies noticeable gaps in the e-learning research; and it concludes with an analysis of some inherent challenges embedded in both conducting meaningful research on the advanced technologies in learning/teaching settings and in their actual implementation.

Computational and Energy Costs of Cryptographic Algorithms on Handheld Devices

Abstract: Networks are evolving toward a ubiquitous model in which heterogeneous devices are interconnected. Cryptographic algorithms are required for developing security solutions that protect network activity. However, the computational and energy limitations of network devices jeopardize the actual implementation of such mechanisms. In this paper, we perform a wide analysis on the expenses of launching symmetric and asymmetric cryptographic algorithms, hash chain functions, elliptic curves cryptography and pairing based cryptography on personal agendas, and compare them with the costs of basic operating system functions. Results show that although cryptographic power costs are high and such operations shall be restricted in time, they are not the main limiting factor of the autonomy of a device.

Quality of Learners' Time and Learning Performance beyond Quantitative Time-on-Task.

Abstract: Along with the amount of time spent learning (or time-on-task), the quality of learning time has a real influence on learning performance. Quality of time in online learning depends on students’ time availability and their willingness to devote quality cognitive time to learning activities. However, the quantity and quality of the time spent by adult e-learners on learning activities can be reduced by professional, family, and social commitments. Considering that the main time pattern followed by most adult e-learners is a professional one, it may be beneficial for online education programs to offer a certain degree of flexibility in instructional time that might allow adult learners to adjust their learning times to their professional constraints. However, using the time left over once professional and family requirements have been fulfilled could lead to a reduction in quality time for learning. This paper starts by introducing the concept of quality of learning time from an online student-centred perspective. The impact of students’ time-related variables (working hours, time-on-task engagement, time flexibility, time of day, day of week) is then analyzed according to individual and collaborative grades achieved during an online master’s degree program. The data show that both students’ time flexibility ( r = .98) and especially their availability to learn in the morning are related to better grades in individual ( r = .93) and collaborative activities ( r = .46).

Spatial attention and conscious perception: the role of endogenous and exogenous orienting

Abstract: Attention has often been considered to be a gateway to consciousness (Posner, Proceedings of the National Academy of Sciences of the United States of America, 91(16), 7398–7403, 1994). However, its relationship with conscious perception (CP) remains highly controversial. While theoretical models and experimental data support the role of attention in CP (Chica, Lasaponara, Lupianez, Doricchi, & Bartolomeo, NeuroImage, 51, 1205–1212, 2010; Dehaene, Changeux, Naccache, Sackur, & Sergent, Trends in Cognitive Sciences, 10, 204–211, 2006; Mack & Rock, Inattentional blindness, 1998), recent studies have claimed that at least some forms of attention—endogenous or top-down spatial attention—are neither sufficient nor necessary for CP (Koch & Tsuchiya, Trends in Cognitive Sciences, 11, 16–22, 2007). In the present experiments, we demonstrate the importance of exogenously triggered attention for the modulation of CP. Weak or null effects were instead observed when attention was triggered endogenously. Our data are discussed in the framework of recent neuropsychological models (Dehaene et al., Trends in Cognitive Sciences, 10, 204–211, 2006), postulating that activity within reverberating frontoparietal networks, as colocalized with spatial--orienting systems, is the brain correlate of consciously processed information.

Energy-Aware Application-Centric VM Allocation for HPC Workloads

Abstract: Virtualized data centers and clouds are being increasingly considered for traditional High-Performance Computing (HPC) workloads that have typically targeted Grids and conventional HPC platforms. However, maximizing energy efficiency, cost-effectiveness, and utilization of data center resources while ensuring performance and other Quality of Service (QoS) guarantees for HPC applications requires careful consideration of important and extremely challenging tradeoffs. An innovative application-centric energy-aware strategy for Virtual Machine (VM) allocation is presented. The proposed strategy ensures high resource utilization and energy efficiency through VM consolidation while satisfying application QoS. While existing VM allocation solutions are aimed at satisfying only the resource utilization requirements of applications along only one dimension (CPU utilization), the proposed approach is more generic as it employs knowledge obtained through application profiling along multiple dimensions. The results of our evaluation show that the proposed VM allocation strategy enables significant reduction either in energy consumption or in execution time, depending on the optimization goals.

The impact of market orientation dimensions on client cooperation in the development of new service innovations

Abstract: Purpose – Culture makes firms unique and, depending on the implemented pattern of social and managerial culture, technology, and innovation, it can have an important influence on the personality and behaviour of the firm. Although a cultural model of market orientation encourages product innovation and fosters cooperative relationships with clients, few studies analyse this important relationship from a service perspective. This research seeks to investigate the relevance of market orientation for the firm's client cooperation relationships in developing radical innovations in the service sector.Design/methodology/approach – A descriptive investigation uses 433 Spanish service firms that introduced radical innovations in their product fields in the past two years. The paper conducted four discriminant analyses: one for the total sample of firms and three for the sub‐samples defined by the extent to which firms use information and communication technologies (ICTs) in their activities.Findings – The four mo...

Emotion Measurement in Intelligent Tutoring Systems: What, When and How to Measure

Abstract: Affective or Emotion oriented computing constitutes an emerging research field that is still in its early stages. The lack of empirical results together with the complexity that attributes emotions, subjects research to a diversity of theories, models and tools. In the current paper we present a critical review of the state of the art on emotion measurement models, methods and tools and we suggest some informal rules towards their realistic use in education settings.

High capacity audio watermarking using the high frequency band of the wavelet domain

Abstract: This paper proposes a novel high capacity robust audio watermarking algorithm by using the high frequency band of the wavelet decomposition at which the human auditory system (HAS) is not very sensitive to alteration. The main idea is to divide the high frequency band into frames and, for embedding, to change the wavelet samples depending on the average of relevant frame's samples. The experimental results show that the method has a very high capacity (about 11,000 bps), without significant perceptual distortion (ODG in [?1 ,0] and SNR about 30dB), and provides robustness against common audio signal processing such as additive noise, filtering, echo and MPEG compression (MP3).

'A New Space for Knowledge and People'? Henri Lefebvre, Representations of Space, and the Production of '22@Barcelona'

Abstract: The Barcelona model of urban transformation has for some time now been considered a paradigmatic case of successful regeneration. Urban change is ongoing in the city, albeit in a changed global context in which cities are increasingly being seen as the principal drivers of economic growth and competitiveness in the ‘new’ or ‘knowledge’ economy. The paper draws on the writing of Henri Lefebvre and on his critique of representations of space, in particular, in order to examine the current strategic transformation of the Poblenou district of Barcelona into 22@Barcelona: An innovation district. The paper endorses Lefebvre's work as a point of departure in critically analysing contemporary strategies to engineer urban competitiveness. It argues that the functionalist and reductive representations of 22@Barcelona betray an ideological concern with the globally competitive abstract space, the reduction of differences, and the closing of the circuit of everyday life in Poblenou.

Key service innovation drivers in the tourism sector: empirical evidence and managerial implications

Abstract: This study highlights the importance of market orientation and the use of information and communication technologies (ICT) as determinants of service innovation activity for companies in the tourism sector. In doing so, the study provides a means to classify companies as innovative or not. Using a sample of 100 Spanish firms from different branches of the tourism sector, we confirm and extend prior research. In particular, market orientation—especially a customer orientation—is critical for developing new services that lead to competitive advantages. In addition, ICT have a dual, direct, and indirect influence on service innovation.

Endowing e-Learning Systems with Emotion Awareness

Abstract: The consideration of emotion in learning has been in the research agenda for quite long time and literature is offering a variety of studies that are evaluating the role of emotions in various learning contexts (class, test and exams, during studying at home, etc). In the current paper we first appose a critical review of prominent emotion taxonomies, affect detection and feedback strategies and then we propose the design of a system that is endowed with students' emotion aware capabilities. An emotion taxonomy that originates from the basic emotions of fear and affection is put forward. Social-Emotional Learning Theory and Practice can be exploited to feed the necessary theoretical background that is lacking of empirical data.

Hybrid Algorithms for Service, Computing and Manufacturing Systems: Routing and Scheduling Solutions

Abstract: Hybrid Algorithms for Service, Computing and Manufacturing Systems: Routing and Scheduling Solutions explores research developments and applications from an interdisciplinary perspective that combines approaches from operations research, computer science, artificial intelligence, and applied computational mathematics. Contributions cover a range of hybrid algorithm theory and practice as it relates to routing, scheduling, and real-life applications.

Surfing the Net: A Pathway to Participation for the Politically Uninterested?

Abstract: This article explores whether use of the Internet changes the role that political motivation has traditionally played in classic explanations of participation. We ask if, by reducing so dramatically the costs of political participation, the Internet causes interest in politics to lose importance as a causal factor of participation. We examine this issue analysing a representative survey of the Spanish population which deals with political participation and Internet use. The results show that use of Internet has a direct effect on participation independently of motivation, and that, in order to participate online, skilled Internet users do not need to be motivated or interested in politics.

Teaching mathematics online in the European Area of Higher Education: an instructor's point of view

Abstract: This article first discusses how information technologies are changing the way knowledge is delivered at universities worldwide. Then, the article reviews some of the most popular learning management systems available today and some of the most useful online resources in the areas of Mathematics and Statistics. After that, some long-term experiences regarding the teaching of online courses in those areas at the Open University of Catalonia are discussed. Finally, the article presents the results of a large-scale survey performed in Spain that aims to reflect instructors’ opinions and feelings about potential benefits and challenges of teaching mathematics online, as well as the role of emergent technologies in the context of the European Area of Higher Education. Therefore, this article contributes to the existing literature as an additional reference point, one based on our long-term experience in a large-scale online environment, for discussions involving mathematical e-learning.

A Practical Implementation Attack on Weak Pseudorandom Number Generator Designs for EPC Gen2 Tags

Abstract: The Electronic Product Code Generation 2 (EPC Gen2) is an international standard that proposes the use of Radio Frequency Identification (RFID) in the supply chain. It is designed to balance cost and functionality. As a consequence, security on board of EPC Gen2 tags is often minimal. It is, indeed, mainly based on the use of on board pseudorandomness, used to obscure the communication between readers and tags; and to acknowledge the proper execution of password-protected operations. In this paper, we present a practical implementation attack on a weak pseudorandom number generator (PRNG) designed specifically for EPC Gen2 tags. We show that it is feasible to eavesdrop a small amount of pseudorandom values by using standard EPC commands and using them to determine the PRNG configuration that allows to predict the complete output sequence.

Narrative comprehension and production in children with SLI: an eye movement study.

Abstract: This study investigates narrative comprehension and production in children with specific language impairment (SLI). Twelve children with SLI (mean age 5;8 years) and 12 typically developing children (mean age 5;6 years) participated in an eye-tracking experiment designed to investigate online narrative comprehension and production in Catalan- and Spanish-speaking children with SLI. The comprehension task involved the recording of eye movements during the visual exploration of successive scenes in a story, while listening to the associated narrative. With regard to production, the children were asked to retell the story, while once again looking at the scenes, as their eye movements were monitored. During narrative production, children with SLI look at the most semantically relevant areas of the scenes fewer times than their age-matched controls, but no differences were found in narrative comprehension. Moreover, the analyses of speech productions revealed that children with SLI retained less information and made more semantic and syntactic errors during retelling. Implications for theories that characterize SLI are discussed.

Análisis de la interacción en ambientes híbridos de aprendizaje

Abstract: El analisis de la interaccion en ambientes virtuales e hibridos es un tema complejo, puesto que es necesario superar la aproximacion cuantitativa, numero de mensajes, y lograr informacion sobre las dinamicas de interaccion, en el marco de las actividades educativas. En este trabajo se presenta un conjunto de estrategias para el analisis de la interaccion, las cuales se disenaron durante el desarrollo de una tesis doctoral, como respuesta a dos retos que fueron identificados: ?como observar la interaccion?, ?como relacionar la interaccion con el rendimiento academico? Las estrategias disenadas ofrecen elementos para el analisis de las actividades educativas, analisis de las discusiones virtuales asincronicas, representacion de las interacciones y la relacion entre la interaccion y el rendimiento academico. El conjunto de estrategias permitio reconocer el fenomeno de la interaccion en el marco de actividades educativas, asi como el proceso o dinamica en la interaccion grupal, que muestra la evolucion del grupo hacia la construccion de conocimiento. Por otro lado, tambien permitio analizar los procesos virtuales de interaccion y establecer comparaciones entre las dinamicas de los grupos y la relacion entre estas y los resultados de rendimiento academico. Si bien el grupo de estrategias surgen en un estudio especifico, ofrecen herramientas que pueden utilizarse en otros contextos. La manera de utilizar las estrategias se ilustra en este articulo con un ejemplo.

The Regulation of Diffusion of Public Sector Information Via Electronic Means: Lessons from the Spanish Regulation

Abstract: Transparency is one of the main challenges for public administrations in the information society to bring the public administrations closer to citizens and finally, to improve their democratic legitimacy. The article focuses on new tools to regulate the diffusion of public sector information and it also contributes some elements which will improve it. This analysis will be done, firstly by examining the various regulations approved in Spain on the diffusion of public sector information through electronic means. In particular, the scope of the Spanish e-Government Act will be analyzed in relation to the diffusion of public sector information through electronic means. Finally, some landmarks will be proposed which can serve to guide the formulation of new regulations on the use of electronic means for diffusing public sector information not only by Spanish public authorities but also by other authorities who intend to pass a regulation in this field to improve transparency.

Food consumption and civil society: Mediterranean diet as a sustainable resource for the Mediterranean area.

Abstract: Objective To define the Mediterranean diet model inside a Mediterranean social and cultural food framework and from the perspective of a local model of consumption. Design Reflexion and review of literature available in relation to the Mediterranean diet, locality and proximity. Setting and subjects Mediterranean region and its populations. Results The Mediterranean local food system under the term Mediterranean diet encourages local production and local consumption. From this perspective, this model takes part of every local Mediterranean lifestyles and encourages sustainability. Conclusions From a local Mediterranean point of view and as a proximity model of consumption, Mediterranean food and diet can be a sustainable resource for the Mediterranean area.