1. Are African stock markets efficient? : a comparative analysis between six African markets, the UK, Japan and the USA in the period of the pandemicRui Dias, João M. Pereira, Luísa Cagica Carvalho, 2022, original scientific article Abstract: The aim of this study is to test and compare the efficient market hypothesis,
in its weak form, on the stock markets of Botswana, Egypt, Kenya, Morocco,
Nigeria, South Africa, Japan, the UK and the USA from 2 September 2019 to 2
September 2020. This study is based on the following research question: has
the global pandemic (COVID-19) reduced the efficiency – in its weak form – of
African financial markets compared to the mature markets of the UK, Japan and
the USA? The results sustain the evidence that the random walk hypothesis is not
supported by the financial markets analysed in the period of the global pandemic.
The variance ratio values are lower than the unit, which implies that the returns
are self-correlated over time. A reversion to the average is also observed, with
no differences identified between mature and emerging financial markets. In
corroboration, the Detrended Fluctuation Analysis (DFA) exponents show that the
financial markets present signs of (in)efficiency in its weak form, thus showing
persistence in the yields. This therefore implies the existence of long memories
validating the results of the variance using the Wright’s Rank and Signs Test
(2000), which prove the rejection of the random walk hypothesis. Keywords: African stock markets, efficient market hypothesis, mean reversion, random walk Published in DKUM: 19.06.2023; Views: 399; Downloads: 20
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2. Long memory in the Croatian and Hungarian stock market returnsMejra Festić, Alenka Kavkler, Silvo Dajčman, 2012, original scientific article Abstract: The objective of this paper is to analyze and compare the fractal structure of the Croatian and Hungarian stock market returns. The presence of long memory components in asset returns provides evidence against the weak-form of stock market effi ciency. The starting working hypothesis that there is no long memory in the Croatian and Hungarian stock market returns is tested by applying the Kwiatkowski-Phillips-Schmidt-Shin (KPSS) (1992) test, Loʼs (1991) modified rescaled range (R/S) test, and the wavelet ordinary least squares (WOLS) estimator of Jensen (1999). The research showed that the WOLS estimator may lead to different conclusions regarding long memory presence in the stock returns from the KPSS and unit root tests or Loʼs R/S test. Furthermore, it proved that the fractal structure of individual stock returns may be masked in aggregated stock market returns (i.e. in returns of stock index). The main finding of the paper is that both the Croatian stock index Crobex and individual stocks in this index exhibit long memory. Long memory is identified for some stocks in the Hungarian stock market as well, but not for the stock market index BUX. Based on the results of the long memory tests, it can be concluded that while the Hungarian stock market is weak form efficient, the Croatian stock market is not. Keywords: stock market, long memory, efficient-market hypothesis, Croatia, Hungary Published in DKUM: 18.07.2017; Views: 1163; Downloads: 100
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3. Šahovski sistem rangiranja za primerjavo evolucijskih algoritmov : doktorska disertacijaNiki Veček, 2016, doctoral dissertation Abstract: Eksperiment na področju evolucijskega računanja lahko povzamemo s štirimi
pomembnimi koraki: načrtovanje eksperimenta, zagon eksperimenta, analiza rezultatov ter interpretacija rezultatov in diskusija. Vsak korak zahteva posebno pozornost in vsebuje določene pasti, na katere moramo kot raziskovalci biti pozorni.
Disertacija podrobno opiše vse štiri korake, s posebnim poudarkom na statistični
analizi rezultatov, in predstavi novo metodo za primerjavo evolucijskih algoritmov - Chess Rating System for Evolutionary Algorithms (CRS4EAs). Predlagana metoda temelji na šahovskem rangiranju, kjer je vsak evolucijski algoritem predstavljen kot šahovski igralec, vsaka primerjava rešitev dveh algoritmov predstavlja igro med dvema igralcema (in se lahko konča z zmago enega in porazom drugega ali remijem), vsaka parna primerjava med več algoritmi pa predstavlja turnir. Osnova za predlagano metodo je šahovski sistem rangiranja Glicko-2, za katerega tekom disertacije tudi pokažemo, da je najprimernejši. Predlagano metodo skozi velik nabor eksperimentov primerjamo s statističnimi testi z ničelno hipotezo in pokažemo, da lahko s predlagano metodo učinkovito primerjamo uspešnosti evolucijskih algoritmov.
Predlagana metoda najde podobne signifikantne razlike kot bi jih našli z uporabo standardnih statističnih metod, hkrati pa omogoča absolutno vrednotenje moči in uspešnosti algoritmov, ki so vključeni v sistem. Predlagano metodo na učinkovit način uporabimo za uglaševanje parametrov evolucijskega algoritma in jo skozi nabor več eksperimentov primerjamo z drugimi metodami uglaševanja (F-Race in Revac). Keywords: evolutionary algorithms, computational experiment, null hypothesis, glicko, chess rating Published in DKUM: 14.09.2016; Views: 1966; Downloads: 255
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4. Linguistic Relativism in the Case of Linguistic Gender and Number: A Comparison between English and SloveneTamara Kovačič, 2016, master's thesis Abstract: The master’s thesis deals with linguistic relativism in the case of grammatical gender and number of two languages: English and Slovene. Firstly, the thesis presents the origins of Sapir-Whorf hypothesis, which is of significant importance for the development of linguistic relativism. The hypothesis met with a wide response amongst researchers: some agreed with the ideas, whereas others did not. Linguistic relativism suggests that the language one speaks shapes their perception of the world. In order to prove such statement, several experiments were conducted. In addition, the thesis outlines the main characteristics of grammatical gender and number in English and the Slovene language. The empirical part includes the analysis of the results of the experiment that was conducted amongst native speakers of English and native speakers of the Slovene language. Both qualitative and quantitative approaches were used for the interpretation of the results. The results show limited influence of the structure of language on the linguistic processing of the speakers, thus only partially supporting Sapir-Whorf hypothesis. In the case of gender categorization the results showed that the Slovene speakers were affected by the grammatical gender. In this respect we can say that language can influence our perception of the world. In the case of grammatical number the Slovene speakers were not more sensitive to the dual. The results thus show limited influence of the structure of language on the linguistic processing of the speakers, thus only partially supporting the Sapir-Whorf hypothesis. Keywords: Sapir-Whorf hypothesis, linguistic relativism, language and thought, grammatical gender and number, experiment Published in DKUM: 15.02.2016; Views: 2149; Downloads: 143
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5. The boundaries of the firm : critiques, strategies and policiesNeil M. Kay, review Keywords: enterprise, economic theories, economists, cognition, keynesianism, acquisitions, mergers, strategic alliances, boundary, business policy, corporations, strategic management, hypothesis, sinergy, economic structures, economic structures, joint venture, integration, business cooperation, management, business efficiency, success of business operation Published in DKUM: 01.06.2012; Views: 2060; Downloads: 47
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