Statistical analysis of emotions and opinions at Digg website

We performed statistical analysis on data from the Digg.com website, which enables its users to express their opinion on news stories by taking part in forum-like discussions as well as directly evaluate previous posts and stories by assigning so called "diggs". Owing to fact that the content of each post has been annotated with its emotional value, apart from the strictly structural properties, the study also includes an analysis of the average emotional response of the posts commenting the main story. While analysing correlations at the story level, an interesting relationship between the number of diggs and the number of comments received by a story was found. The correlation between the two quantities is high for data where small threads dominate and consistently decreases for longer threads. However, while the correlation of the number of diggs and the average emotional response tends to grow for longer threads, correlations between numbers of comments and the average emotional response are almost zero. We also show that the initial set of comments given to a story has a substantial impact on the further "life" of the discussion: high negative average emotions in the first 10 comments lead to longer threads while the opposite situation results in shorter discussions. We also suggest presence of two different mechanisms governing the evolution of the discussion and, consequently, its length.Comment: 26 pages, 16 figures, 6 table

Ewaluacja ryzyka w zarządzaniu kryzysowym

Investigations of the situation characterized by uncertainty and risk in the last century, particularly in situations of crisis and conflict, were carried out at different levels of generality and specificity. In this article, the methodological foundations of risk evaluation models in situations of threats to system security are described. The general decision model in circumstances of risk and uncertainty and statistical risk measurement methods for crisis management are depicted. The examples of the mathematical models of the risk evaluations are also presented.W artykule przedstawiono koncepcję metodologicznych podstaw ewaluacji ryzyka w sytuacjach zagrożeń bezpieczeństwa systemu. Przedstawiono ogólny model decyzyjny w warunkach niepewności i ryzyka oraz statystyczne miary ryzyka na potrzeby zarządzania przedsięwzięciami. Omówiono proces ewaluacji ryzyka w systemie zarządzania kryzysowego. W artykule zamieszczono przykłady modeli matematycznych ewaluacji ryzyka

Wyzwania i zagrożenia bezpiecznego rozwoju społeczeństwa informacyjnego

Modem security systems in information society, both national and international, require the consideration of new possibilities, risk and dangers. Information threats, cyber terror­ism and info wars are new challenges for security and peace

Universal scaling of distances in complex networks

Universal scaling of distances between vertices of Erdos-Renyi random graphs, scale-free Barabasi-Albert models, science collaboration networks, biological networks, Internet Autonomous Systems and public transport networks are observed. A mean distance between two nodes of degrees k_i and k_j equals to =A-B log(k_i k_j). The scaling is valid over several decades. A simple theory for the appearance of this scaling is presented. Parameters A and B depend on the mean value of a node degree _nn calculated for the nearest neighbors and on network clustering coefficients.Comment: 4 pages, 3 figures, 1 tabl

A veritable zoology of successive phase transitions in the asymmetric qq-voter model on multiplex networks

We analyze a nonlinear $q$-voter model with stochastic noise, interpreted in the social context as independence, on a duplex network. The size of the lobby $q$ (i.e., the pressure group) is a crucial parameter that changes the behavior of the system. The $q$-voter model has been applied on multiplex networks in a previous work [Phys. Rev E. 92. 052812. (2015)], and it has been shown that the character of the phase transition depends on the number of levels in the multiplex network as well as the value of $q$. Here we study phase transition character in the case when on each level of the network the lobby size is different, resulting in two parameters $q_1$ and $q_2$. We find evidence of successive phase transitions when a continuous phase transition is followed by a discontinuous one or two consecutive discontinuous phases appear, depending on the parameter. When analyzing this system, we even encounter mixed-order (or hybrid) phase transition. We perform simulations and obtain supporting analytical solutions on a simple multiplex case - a duplex clique, which consists of two fully overlapped complete graphs (cliques).Comment: 13 pages, 10 figure

Response of winter oilseed rape to differentiated foliar fertilisation

This article presents results of a three-year field experiment laid out on medium textured soil, in north-eastern Poland. Winter oilseed rape was sprayed with foliar fertilisers AgravitaActive 48 (AA48) - NPK 8:8.7:16.6 and AgravitaActive70 (AA70) - NPK 10:22.7:6.6 at different phases of the crop’s vegetative growth (BBCH 14, BBCH 35). The impact of the fertilisers on the yield of seeds, straw, total protein, crude fat, and on the content of macro- and micronutrients in aerial parts (BBCH 20 and 89) and roots (BBCH 20) of oilseed rape was evaluated. Foliar nutrition of oilseed rape plants with AA48 and AA70 significantly increased the seed yield of oilseed rape. The best yield-stimulating effect was achieved after the application of AA48 in autumn. Fertilisation of oilseed rape in that season of the year caused an increase in seed yield by 430 kg ha-1. Each fertiliser contributed to a rise in the yield of protein and yield of crude fat but had no effect on the content of magnesium, copper, and zinc in seeds

Determinanty rozwoju społeczeństwa informacyjnego

Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej nauk

Log-periodic oscillations due to discrete effects in complex networks

We show that discretization of internode distribution in complex networks affects internode distances l_ij calculated as a function of degrees (k_i k_j) and an average path length as function of network size N. For dense networks there are log-periodic oscillations of above quantities. We present real-world examples of such a behavior as well as we derive analytical expressions and compare them to numerical simulations. We consider a simple case of network optimization problem, arguing that discrete effects can lead to a nontrivial solution.Comment: 5 pages, 5 figures, REVTE