Search results for "Data Warehouse"
showing 10 items of 332 documents
Introducing the Temporal Distortion Index to perform a bidimensional analysis of renewable energy forecast
2016
Abstract Wind has been the largest contributor to the growth of renewal energy during the early 21st century. However, the natural uncertainty that arises in assessing the wind resource implies the occurrence of wind power forecasting errors which perform a considerable role in the impacts and costs in the wind energy integration and its commercialization. The main goal of this paper is to provide a deeper insight in the analysis of timing errors which leads to the proposal of a new methodology for its control and measure. A new methodology, based on Dynamic Time Warping, is proposed to be considered in the estimation of accuracy as attribute of forecast quality. A new dissimilarity measure…
Field Measurements and Parameter Calibrations of Propagation Model for Digital Audio Broadcasting in Norway
2018
During 2017, digital audio broadcasting (DAB) replaces frequency modulation (FM) broadcasting and becomes the only technology for national terrestrial audio broadcasting services in Norway. As Norway is the first country that replaces FM completely with DAB, it is of great importance to measure the signal strength of such a technology in massive deployments and to tune a simulation model as a reference for future studies. Therefore, field measurements of received signal strength are carried out in a typical Norwegian area in this work. Based on the data obtained from the measurements, a simulator with a recent empirical propagation model, namely, ITU-R P.1546-5, has been calibrated. The fin…
How the Atmospheric Variables Affect to the WLAN Datalink Layer Parameters
2010
There are many issues that affect to WLAN connections (walls, vegetation, rain, objects in the Fresnel zone, etc.). Network designers and telecommunication practitioners must take them into account when they are planning wireless connections between devices. Some studies have demonstrated the implication of the atmospheric variables in the frequency attenuation and in the line of sight of the waves. But, to the extend of our knowledge, there is not any work published that relates the atmospheric variables with the datalink layer parameters of the WLANs. We must take into account that the datalink layer allows us to measure quite more parameters than the physical layer. After a review of the…
Water quality indicators: Comparison of a probabilistic index and a general quality index. The case of the Confederación Hidrográfica del Júcar (Spai…
2010
Abstract The main objective of this work is to measure water quality using a stochastic index built with tools of Probability Theory. Its great advantage is that it accounts for the underlying uncertainty in quality classification that results from variations in the data for individual physical and chemical characteristics, considering them as random variables. We compare the results obtained by measuring water quality with this index (the probabilistic index, PI ) and a classical deterministic index (the general quality index, GQI ). Also we do a comparison with other usual indices in order to validate the PI index. To demonstrate the application of PI and GQI indices, we used information …
A methodology for the reduction of imprecision in the engineering process
1997
Abstract Engineering design is characterized by a high level of imprecision, vague parameters, and ill-defined relationships. In design, imprecision reduction must occur to arrive at a final product specification. Few design systems exist for adequately representing design imprecision, and formally reducing it to precise values. Fuzzy set theory has considerable potential for addressing the imprecision in design. However, it lacks a formal methodology for system development and operation. One repercussion of this is that imprecision reduction is, at present, implemented in a relatively ad-hoc manner. The main contribution of this paper is to introduce a methodology called precision converge…
A survey of serendipity in recommender systems
2016
We summarize most efforts on serendipity in recommender systems.We compare definitions of serendipity in recommender systems.We classify the state-of-the-art serendipity-oriented recommendation algorithms.We review methods to assess serendipity in recommender systems.We provide the future directions of serendipity in recommender systems. Recommender systems use past behaviors of users to suggest items. Most tend to offer items similar to the items that a target user has indicated as interesting. As a result, users become bored with obvious suggestions that they might have already discovered. To improve user satisfaction, recommender systems should offer serendipitous suggestions: items not …
Destination image
2002
Abstract This paper presents a review and discussion of the concept and measurement of destination image, within an intradisciplinary marketing perspective. Both theoretical and methodological aspects of this concept and measurement are treated. Based on the existence of three dimensions of object, subject and attributes, previous studies are analyzed. A taxonomy of the methodological and statistical procedures for measuring the image of the destinations is also proposed in order to help researchers to capture and measure the image construct. The paper proposes a conceptual model featuring its complex, multiple, relativistic and dynamic nature as a more comprehensive framework of destinatio…
A Survey on how to Cross-Reference Web Information Sources
2015
International audience; The goal of giving information a well-defined meaning is currently shared by different research communities. Once information has a well-defined meaning, it can be searched and retrieved more effectively. Therefore, this paper is a survey about the methods that compare different textual information sources in order to determine whether they address a similar information or not. The improvement of the studied methods will eventually lead to increase the efficiency of documentary research. In order to achieve this goal, the first category of methods focuses on semantic measure definitions. A second category of methods focuses on paraphrase identification techniques, an…
Measuring hospital service quality: a methodological study
1999
Quality in the service sector has been extensively researched during the last years. The publication of a sequence of measurement tools has allowed homogenizing the study of this issue. The object of the present work is to develop a methodological analysis for the use of the SERVQUAL measure scale in the Spanish public health sector. We analyse the reliability of this measure scale, its dimensionality, using comparison with other studies. Finally we consider the main criticism frequently made in the literature.
Application of GPS technology to measurements of displacements of high-rise structures due to weak winds
2002
Abstract Global positioning systems (GPS) have been developed for military purposes like single-point positioning and navigation. The first non-military applications have been made for geodetic purposes with base-line measurements using differential methods. We introduce GPS technology as an alternative measurement method of displacements when high-rise structural systems are monitored. In this paper, two tests to evaluate the accuracy of the measurements using GPS are presented. Then the evaluation of ability of GPS to measure small movements of the Stuttgart TV-tower and the industrial chimney of Opole power station due to weak winds are also given.