Search results for "STATISTICS"

Restrictive Factors for Micro-Company Growth in Latvia

2020

Every country is interested in entrepreneurship development as entrepreneurs form the basis for economic development, so academic researchers are looking for supportive and restrictive factors in business development. In Latvia, the majority of companies are micro and small enterprises. The aim of the paper is to investigate the restrictive factors related to the successful development of the company in Latvia, depending on the number of employees. Tasks of the research - evaluate the limiting factors influencing the development of micro-companies; find the most important factors that limit the involvement of employees and experienced managers in companies in the country, regions; compare t…

Population processes under the influence of disasters occurring independently of population size

1989

Markov branching processes and in particular birth-and-death processes are considered under the influence of disasters that arrive independently of the present population size. For these processes we derive an integral equation involving a shifted and rescaled argument. The main emphasis, however, is on the (random) probability of extinction. Its distribution density satisfies an equation which can be solved numerically at least up to a multiplicative constant. In an example it is also found by simulation.

The use of Markovian metapopulation models: Reducing the dimensionality of transition matrices by self-organizing Kohonen networks

2006

Abstract Markovian population models are used in conservation biology to find an accurate estimate of a population's extinction probability. Such models require handling of large transition matrices and calculations are thus extremely time-consuming when large populations have to be studied. To accomplish these problems, some authors have suggested to group together several states/sizes of the population. Unfortunately, this so-called binning frequently results in errors in estimates obtained. The main problem with binning is that it assumes that grouped states behave nearly identical with respect to the underlying stochastic population process and that so far binning methods implicitly vio…

Noise in ecosystems: a short review

2004

Noise, through its interaction with the nonlinearity of the living systems, can give rise to counter-intuitive phenomena such as stochastic resonance, noise-delayed extinction, temporal oscillations, and spatial patterns. In this paper we briefly review the noise-induced effects in three different ecosystems: (i) two competing species; (ii) three interacting species, one predator and two preys, and (iii) N-interacting species. The transient dynamics of these ecosystems are analyzed through generalized Lotka-Volterra equations in the presence of multiplicative noise, which models the interaction between the species and the environment. The interaction parameter between the species is random …

A geometrical framework for f –statistics

2020

AbstractA detailed derivation of the f–statistics formalism is made from a geometrical framework. It is shown that the f–statistics appear when a genetic distance matrix is constrained to describe a four population phylogenetic tree. The choice of genetic metric is crucial and plays an outstanding role as regards the tree–like–ness criterion. The case of lack of treeness is interpreted in the formalism as presence of population admixture. In this respect, four formulas are given to estimate the admixture proportions. One of them is the so–called f4–ratio estimate and we show that a second one is related to a known result developed in terms of the fixation index FST. An illustrative numerica…

Assessment of Organizational Trust: Preliminary Data for Romanian Adaptation of the Organizational Trust Inventory Short Form

2013

Abstract In the last years, trust became an important variable in regard to the well-being of organizations. In Romania, it was included in studies as a variable but there are few instruments that measure organizational trust. Therefore I identify a necessity for developing instruments useful in assessing and promoting any organizational adjustments. This paper presents the preliminary data obtained in the process of adaptation of OTI for the Romanian population. In doing so, we followed the guidelines of ITC. Using a sample of 108 employees the psychometric results show that OTI-RO has a high level of internal consistency reliability (a = 0.94) and it can be used exclusive for equivalent p…

Jumping To Conclusions, General Intelligence, And Psychosis Liability: Findings From The Multi-Centre EU-GEI Case-Control Study

2019

AbstractBackgroundThe “jumping to conclusions” (JTC) bias is associated with both psychosis and general cognition but their relationship is unclear. In this study, we set out to clarify the relationship between the JTC bias, IQ, psychosis and polygenic liability to schizophrenia and IQ.Methods817 FEP patients and 1294 population-based controls completed assessments of general intelligence (IQ), and JTC (assessed by the number of beads drawn on the probabilistic reasoning “beads” task) and provided blood or saliva samples from which we extracted DNA and computed polygenic risk scores for IQ and schizophrenia.ResultsThe estimated proportion of the total effect of case/control differences on J…

2021

The Depressive and Anxious Avoidance in Prolonged Grief Questionnaire (DAAPGQ) was developed to measure depressive and anxious avoidance behaviors, which, according to cognitive-behavioral models, are supposed to play an important role in the development and maintenance of prolonged grief. The present study aimed to develop a German version of the DAAPGQ and evaluate its psychometric properties and validity within a representative sample of the German general population (N = 2531). The German-language DAAPGQ was developed using a forward-backward translation procedure. Then, a subsample of individuals who reported having lost a significant other (N = 1371) of a representative sample was ass…

2019

The Trier Inventory for Chronic Stress (TICS), consisting of 57 items, is an instrument for measuring chronic stress in nine areas. There is also a short form (SSCS) of the TICS consisting of 12 items. However, this 12-item short form does not include all nine areas of the theoretical model and the long version. Therefore, a short version including all nine scales/areas was investigated. The TICS was taken by a sample of N = 2,473 respondents from the general population, aged 14 to 99, selected by random-route sampling. Confirmatory factor analyses applying robust maximum likelihood estimations (MLM) tested the model fit. The one-factor-model proposed by the original authors was tested, and…

Anthropological investigation of a Kurdish village population from south-eastern Turkey. I. Regional comparison of morphological features

1988

The paper is dealing with an anthropological investigation of a Kurdish village population from southern Turkey. We especially attached importance on the complete registration of all inhabitants to get a reliable sample for regional comparison of morphological features. Anthropological data of other Kurdish population groups are used for univariate and multivariate analysis. The resulting clusters are discussed beside the question of representation under the standpoint of regional and cultural origin of the samples.