Search results for "Information Systems."
showing 10 items of 1545 documents
Stochastic dynamical modelling of spot freight rates
2014
Based on empirical analysis of the Capesize and Panamax indices, we propose different continuous-time stochastic processes to model their dynamics. The models go beyond the standard geometric Brownian motion, and incorporate observed effects like heavy-tailed returns, stochastic volatility and memory. In particular, we suggest stochastic dynamics based on exponential Levy processes with normal inverse Gaussian distributed logarithmic returns. The Barndorff-Nielsen and Shephard stochastic volatility model is shown to capture time-varying volatility in the data. Finally, continuous-time autoregressive processes provide a class of models sufficiently rich to incorporate short-term persistence …
Spatial analysis of the relationship between mortality from cardiovascular and cerebrovascular disease and drinking water hardness
2004
Journal Article; Research Support, Non-U.S. Gov't; Reproduced with permission from Environmental Health Perspectives. Previously published scientific papers have reported a negative correlation between drinking water hardness and cardiovascular mortality. Some ecologic and case-control studies suggest the protective effect of calcium and magnesium concentration in drinking water. In this article we present an analysis of this protective relationship in 538 municipalities of Comunidad Valenciana (Spain) from 1991-1998. We used the Spanish version of the Rapid Inquiry Facility (RIF) developed under the European Environment and Health Information System (EUROHEIS) research project. The strateg…
Gesture recognition using low-cost devices: Techniques, applications, perspectives
2016
Negli ultimi anni abbiamo assistito ad una grande diffusione dei cosiddetti “Kinect-like devices”, ovvero dispositivi basati su un insieme di sensori a basso costo, che consentono di ottenere un’immagine di profondità della scena ripresa. L’alta accessibilità di questi dispositivi, principalmente in termini di costi, ne ha facilitato la diffusione nell’ambito del riconoscimento dei gesti in numerose applicazioni, sia commerciali che di ricerca. In questo articolo saranno inizialmente illustrati i principi generali su cui si fondano le principali tecniche utilizzate per riconoscere i gesti, sfruttando i dati ottenibili dai dispositivi “Kinect-like”. Successivamente, saranno presentati alcuni…
SYSTEMS DECOMPOSITION AND COUPLING
1993
In order to handle efficiently complex models of real systems, it is a convenient practice to decompose them into subsystems that are validated independently. The next step would be joining the subsystems into a global system and performing a new global validation. A formalization of this process is performed as a consequence of practical experience with a model generator expert system based on general systems theory.
Simulation of the anomalous social behaviours with a learning model
2010
In this paper our objective is to understand the process of emergence in the study of social behaviours evolution with a learning model. When the system is too complex to study it is important to recreate an artificial universe in which experiments’ simulation can help to understand the mechanisms of human social behaviours. In Previous work we determined the conditions that favour the perpetuity of the Capitalist Globalization, the possibility of its overcoming with a Free Scientific Society and the possibility of the Ecological Hecatomb. In this paper we have theoretically explained the emergence of the anomalous behaviours and developed statistical studies of the conditions that favour t…
SIMULATING DEMOGRAPHY AND HUMAN DEVELOPMENT DYNAMICS
2014
[EN] A deterministic/stochastic model in which the demographic and the well-being subsystems of a country are involved and related is presented as a way to approach human development. The demographic subsystem is a side-by-side, single-gender, age-structured population dynamic model. The well-being subsystem states the dynamics of the United Nations Hybrid Human Development Index. The model has been validated in the case of Spain and Belgium. Some simulations have been performed with the model for the case of Spain in the 2009-2020 period to determine strategies and scenarios that could increase the life expectancy at birth per gender. Copyright © 2014 Taylor & Francis Group, LLC.
Social Media as Public Sphere: A Stakeholder Perspective
2016
Purpose This paper aims to examine major stakeholders’ communication preferences in eParticipation initiatives and discuss how this affects the public sphere. Despite the potential of social media, it has proven difficult to get people actively involved in the decision-making processes. There is a need for more research on how stakeholders manage and use social media to communicate. Design/methodology/approach The study was conducted as a qualitative case study. Data sources include interviews, social media content, document analysis and field notes. Findings Communication preferences of stakeholders vary according to their salience level. Stakeholders with higher salience are less likely …
Simulation models in eGovernment using system dynamics: A literature survey
2016
System Dynamics (SD) is a method to build simulation models using computers, to study the behaviour of systems, and apply what-if scenarios aiming at achieving optimal policy design. To have an overview of the current state-of-the-art of SD use in the eGovernment field; we have surveyed related literature. Our main goal is to uncover the possibilities for future research by clarifying the shortages. The identified literature is not very large. In most of the literature, SD models use was limited to SD practitioners. We discovered low usage of Group Model Building and workshops despite their usefulness in involving non-SD practitioners in the model building process. Additionally, there is a …
Affordances and effects of introducing social media within eParticipation-Findings from government-initiated Indonesian project
2018
The Current State of Social Media Research for eParticipation in Developing Countries: A Literature Review
2016
While there is an increasing interest for conducting research on the importance of social media within the eParticipation area, more emphasis is still needed within the context of developing countries. We address this need by presenting a literature review on social media within eParticipation in developing countries, to add to the understanding of how these technologies influence the political environment. We discuss trends, contributions and challenges within this area, and propose a future research agenda. Furthermore, we propose a model of social media for eParticipation from a process view perspective to guide future research in this field.