Search results for "a posteriori"

Toward a Quality Guide to Facilitate the Transference of Analytical Methods from Research to Testing Laboratories: A Case Study

2009

Abstract At present, there is no single viewpoint that defines QA strategies in analytical chemistry. On the other hand, there are no unique protocols defining a set of analytical tasks and decision criteria to be performed during the method development phase (e.g., by a single research laboratory) in order to facilitate the transference to the testing laboratories intending to adapt, validate, and routinely use this method. This study proposes general criteria, a priori valid for any developed method, recommended as a provisional quality guide containing the minimum internal tasks necessary to publish new analytical method results. As an application, the selection of some basic internal qu…

A local post-retrieval tool for satellite precipitation estimates

2012

As illustrated by several literature case studies spread around di erent geographic locations, satellite precipi- tation estimates, obtained by means of consolidated algorithms, often result being considerably biased. Moreover observed bias is related to geographic location since particular features such as latitude, presence of coastal areas and climatological and weather regime, a ect performances of satellite estimates. Bias adjusted products that make use of global ground-based precipitation estimates, are available as well but still these datasets may show a relevant bias level. In this study a procedure to bias-adjust satellite precipitation estimates has been devel- oped for the loca…

A Unified Approach to Measuring Accuracy of Error Indicators

2014

In this paper, we present a unified approach to error indication for elliptic boundary value problems. We introduce two different definitions of the accuracy (weak and strong) and show that various indicators result from one principal relation. In particular, this relation generates all the main types of error indicators, which have already gained high popularity in numerical practice. Also, we discuss some new forms of indicators that follow from a posteriori error majorants of the functional type and compare them with other indicators. Finally, we discuss another question related to accuracy of error indicators for problems with incompletely known data.

On the Difference between a-priori and observed statistical power - A comment on "statistical power and sample size calculations: A primer for pediat…

2019

Integration of onshore and offshore seismic arrays to study the seismicity of the Calabrian Region: a two steps automatic procedure for the identific…

2014

Abstract. We plan to deploy in the Taranto Gulf some Ocean Bottom broadband Seismometer with Hydrophones. Our aim is to investigate the offshore seismicity of the Sibari Gulf. The seismographic network optimization consists in the identification of the optimal sites for the installation of the offshore stations, which is a crucial factor for the success of the monitoring campaign. In this paper, we propose a two steps automatic procedure for the identification of the best stations geometry. In the first step, based on the application of a set of a priori criteria, the suitable sites to host the ocean bottom seismic stations are identified. In the second step, the network improvement is eval…

Computer-aided synthesis of complex pump and valve operations

1988

Abstract Process plant operators often have to synthesize sequences of valve and pump operations. On large plants there may be so many possible pipe routes and vessels that it is not practical to provide a priori computer support for every possible operation. The paper describes a program that could form the basis of an operator aid to synthesize appropriate operations from a knowledge of the plant layout and existing pumping operations. The paper concentrates on finding paths through the pipework and on generating a sequence of operations that establishes the path whilst simultaneously satisfying other safety and operating constraints. The paper includes two example problems which were use…

Guaranteed Error Bounds I

2014

In Chap. 3, we discussed the main ideas of fully reliable error control methods and the corresponding numerical algorithms with the paradigm of simple elliptic type problems. This chapter is intended to show a deep connection between a posteriori estimates of the functional type and physical relations generating the problem. Also, the goal of this chapter is to consider a wider set of problems arising in various applications and explain things in terms of computational mechanics. For this purpose, we begin with a simple class of mechanical problems (straight beams) and after that consider curvilinear beams and more complicated models of continuum mechanics (linear elasticity, viscous fluids…

A Posteriori Methods

1998

A posteriori methods could also be called methods for generating Pareto optimal solutions. After the Pareto optimal set (or a part of it) has been generated, it is presented to the decision maker, who selects the most preferred among the alternatives. The inconveniences here are that the generation process is usually computationally expensive and sometimes in part, at least, difficult. On the other hand, it is hard for the decision maker to select from a large set of alternatives. One more important question is how to present or display the alternatives to the decision maker in an effective way. The working order in these methods is: 1) analyst, 2) decision maker.

Building Composite Indicators With Unweighted-TOPSIS

2023

Composite indicators have been widely used in a large number of fields, including innovation and entrepreneurship as a useful tool for conveying summary information about overall performance in a relatively simple way. The construction of composite indicators implies several stages concerning collection of data, selection of criteria and individual indicators, normalization and weighting of criteria and indicators, aggregation, and comparison of overall performance of the alternatives or options. This article aims at contributing to the construction of synthetic indicators by showing with a real example, how the proposed methodology can overcome the problem of the establisment of the decisi…

A Data Association Algorithm for People Re-Identification in Photo Sequences

2010

In this paper, a new system is presented to support the user in the face annotation task. Every time a photo sequence becomes available, the system analyses it to detect and cluster faces in set corresponding to the same person. We propose to model the problem of people re-identification in photos as a data association problem. In this way, the system takes advantage from the assumption that each person can appear at most once in each photo. We propose a fully automated method for grouping facial images, the method does not require any initialization neither a priori knowledge of the number of persons that are in the photo sequence. We compare the results obtained with our method and with s…