6,238 research outputs found
Implicit Logic in Managerial Discourse: A Case Study in Choice of Selection Criteria
Little attention has been paid in mainstream selection theory to how selectors choose to justify criteria and whether there is evidence of any consistency or logic in the manner in which they do so. This paper addresses these questions within a socio-cognitive framework. A newly developed coding system is used to analyse and explain the discourse of 22 managers in justifying selection criteria for technical operators in a European broadcasting company. It was found that, even for a very technical position, managers with experience of the job for which candidates were being selected were more concerned with the values, beliefs and personalities of candidates. It also was found that, independently of their different levels of seniority and experience of selection or interviewing, all managers are more concerned with Person-Organisation Fit for both present and future needs than with immediate Person-Job Fit. The consistency of the findings suggests that there is an ‘implicit logic’ in the manner in which managers as selectors adopt criteria derived from implicit learning and tacit knowledge of both operational and organisational experience.
Economic Policies and Bankruptcy Institutions: Brazil in a Period of Transition from Colony to Independent Nation
This paper studies the legislation on bankruptcy introduced into Brazil by D.João VI (1808-1821) and shows how this legislation was used in this period as an instrument of protection for certain specific economic activities. On one hand, this work deliberately seeks to incorporate institutions into the study of Brazilian economic history, based on the assumption that the lack of interest in the role played by these institutions has hindered a better understanding of the country’s economic development during the Nineteenth Century. On the other hand, this paper introduces new material for the purpose of re-assessing the economic policies enforced in this period. In fact the study of the bankruptcy legislation suggests that one of the Government’s main concern at the time was to promote the development of activities directly related to gold and sugar exports. Therefore the general and popular acceptance of the revolutionary character of the economic policy in this period is challenged.Institutions, Bankruptcy, D. João VI, Legislation
Data mining and quality in service industry: review and some applications
In Service Industry the main goal of Data Mining is to improve the Quality of the interface and the interaction between the organization system and the respective costumers and needs. Now-a-days with the technological advances, a new challenge on exploring data and extrapolating patterns has emerged. Data mining, as an exploratory data analysis tool used in large and complex data sets, allow discovering new snippets of knowledge and patterns in these vast amounts of data, and this is very often crucial on information leading to a higher position, in very competitive markets. In our work we will review some applications of Data Mining in Service Industry and explore some Quality related topics
Elementos de estatística descritiva
Pretende-se com o presente texto, uma abordagem aos principais tópicos usualmente desenvolvidos em Estatística Descritiva, para apoio ao módulo introdutório sobre Estatística Descritiva inserido na unidade curricular de Matemática do Curso de Qualificação para Estudos Superiores da Universidade Aberta. O principal objetivo é fornecer e/ou relembrar um conjunto de conceitos, habitualmente adquiridos pelos estudantes ao nível do ensino secundário, que permita uma melhor adaptação às unidades curriculares da área da estatística lecionadas em licenciaturas das áreas da matemática, informática, ciências, economia e gestão
BIB designs with repeated blocks: review and perspectives
Experimental Design plays an important role on establishing an interface between Applied
Mathematics and statistical applications in several fields, like Agriculture, Industry, Genetics,Biology and Education Sciences. The goal of any Experimental Design is to obtain the maximum amount of information for a given experimental effort, to allow comparisons between varieties and to control for sources of random variability. Randomized block designs are used to control for these sources. A Balanced Incomplete Block Design (BIB Design) is a randomized
block design with number of varieties greater than the block size and with all pairs of varieties occurring equally often along the blocks. The Fisher related information of a balanced block design will remain invariant whether or not the design has repeated blocks. This fact can be used
theoretically to build a large number of non-isomorphic designs for the same set of design
parameters, which could be used for many different purposes both in experimentations and surveys from finite populations. The original and most important method on the construction of BIB Designs with repeated blocks (BIBDR) is due to Hedayat and Li (1979): the trade-off method. Since then, many authors and researchers have been paying particular attention to the
construction of BIBDR, but still some unsolved problems remain. This issue will be briefly reviewed and new results on the existence and construction of BIBDR, as well as several unsolved problems for further research will be presented.Centro de Estatística e Aplicações da Universidade de Lisbo
Application of BIBDR in health sciences using R
Conferência realizada em Rhodes, Grécia, de 23-28 de setembro de 2019.The role of Experimental Design is very well known, considering applications to a broad range of areas, such as
Agriculture, Biology, Medicine, Industry, Education, Economy, Engineering and Food Consumption Sciences. Motivated by the
variety of problems faced in the several areas and simultaneously taking advantage of the emerging technological developments,
new theoretical results, as well as new designs and structures, have been developed by researchers and practitioners accordingly to
the needs. Experimental Design got a place among the most important statistical methodologies and, mainly because of allowing
to separate variation sources, since the last century it has been strongly recommended for Health Sciences studies. In this area,
particular attention has been devoted to Randomized Complete Block Designs and to Balanced Incomplete Block Designs (BIBD)
- which allow testing simultaneously a number of treatments bigger than the block size. Thus, after a brief review of some particular
BIBD properties and of BIBDR - Balanced Incomplete Blocks with Block Repetition, an applications to Health Sciences simulated
data is illustrated, by exploring R softwareinfo:eu-repo/semantics/publishedVersio
The impact of distributional shape on the power of randomization tests for two independent groups: a simulation study using small balanced samples
The importance of randomization tests is very well known in experimental research,
particularly in biometry. The aim of the resent research is to evaluate the impact of
distributional shape on the power of the randomization test for difference between the
means of two independent groups (with n1=n2=16). To manipulate shape in terms of
asymmetry and kurtosis, we used g-and-h distributions. We evaluated the power of the
randomization test, and also the power of the Student-t test, as a comparison standard,
with data simulated from 12 g-and-h distributions for seven values of effect size. For each condition, we generated 20000 samples, and for each one the power of randomization tests was estimated using 1000 permutations. We set the value of Type I
error probability at 0.05. The results show gains in power for both tests with increasing
skewness and/or kurtosis, with a slight advantage for the randomization tests over the Student-t test
From puzzle pieces to masterpiece: connecting strengths between risk analysis, incomplete block designs, data science, and artificial intelligence
info:eu-repo/semantics/publishedVersio
WORKSHOP ON SOME PROSPECTIVE ASPECTS IN MATHEMATICS AND STATISTICS
Constantino Lagoa: In this talk, we discuss some preliminary results on a general approach to chance constrained algebraic problems. In this type of problems, one aims at maximizing the probability of a set defined by polynomial inequalities. This class of problems is quite general and includes many problems in control systems where the system of interest is subject to stochastic disturbances and/or random uncertainty.
Maximizing probability of a semialgebraic set is, in general, non-convex and computationally complex. With the objective of developing systematic numerical procedures to solve such problems, a sequence of convex relaxations is provided, whose optimal value is shown to converge to solution of the original problem. In other words, we provide a sequence of convex (semidefinite) programs of increasing dimension and complexity which can arbitrarily approximate the solution of the probability maximization problem. ### Maria do Rosário Ramos: Hidden Markov Models (HMM) form a class of stochastic process models with a wide range of application in signal processing like speech recognition, image processing, telecommunications, and others like finance and protein research. HMM extend the Markov model s to include the case where the observation is a probabilistic function of the state. The model is based on a Markov chain {Xi} which describes the evolution of a state of a system. Given a realized sequence of state variables {xi}, the observed variables {Yt} are conditionally independent, with a distribution law in each xi. In this talk we will review the three main questions that we can ask about an HMM, and some results for their existence. The Maximum Likelihood Estimation for a HMM is addressed, the difficulties that arise when we try to solve this optimization problem for a given a sequence of observations of {Yt} and unknown parameters. The focus will be the trade off between the maximum likelihood and number of states of the underlying Markov Model, for particular output process. This is joint work with M. Oliveira (UÉ) and Lagoa, C. (Penn State, USA). ### Fernando Costa: We consider a model of cluster annihilation, and point out its difference relative to more common models of cluster coagulation and fragmentation, such as Smoluchowski’s equation. WE briefly present some recent results on the behaviour of solutions and point to some work still in progress. This is joint work with J.T.Pinto (IST) and R. Sasportes (UAb). ### Joaquim Correia: As nonlinear hyperbolic partial differential equations have non unique global solutions, I am concerned with two, related, issues: what about physical solutions? and when can we use such a type of equations
- …