More for less : on consumer rationality and bargaining power on telecommunication markets

We analyse the large scale agent-based model of a prepaid telecommunication market with oligopolistic competition, heterogeneous calling patterns and different levels of agent rationality. We apply innovative implementation approach of utilizing high performance CUDA computing devices which allows us to consider population of up to 1 million consumers. We measure influence of a call graph structure, intra-family network choice coordination and agent rationality level on the market equilibrium. We discover that boundedly rational subscribers, who exploit simple decision heuristics to coordinate network choice within closed user groups, exert much stronger pressure on suppliers than fully rational ones. This leads to lower average calling costs, increased welfare and decreased monopolistic power of operators. We also observe asymmetry in operator margins and volume of on-net and off-net calls in accordance with empirical facts

Properties and Performance of the ABCDe Random Graph Model with Community Structure

In this paper, we investigate properties and performance of synthetic random graph models with a built-in community structure. Such models are important for evaluating and tuning community detection algorithms that are unsupervised by nature. We propose ABCDe, a multi-threaded implementation of the ABCD (Artificial Benchmark for Community Detection) graph generator. We discuss the implementation details of the algorithm and compare it with both the previously available sequential version of the ABCD model and with the parallel implementation of the standard and extensively used LFR (Lancichinetti--Fortunato--Radicchi) generator. We show that ABCDe is more than ten times faster and scales better than the parallel implementation of LFR provided in NetworKit. Moreover, the algorithm is not only faster but random graphs generated by ABCD have similar properties to the ones generated by the original LFR algorithm, while the parallelized NetworKit implementation of LFR produces graphs that have noticeably different characteristics.Comment: 15 pages, 10 figures, 1 tabl

The spectrum of malignancies among adult HIV cohort in Poland between 1995 and 2012 : a retrospective analysis of 288 cases

THE AIM OF THE STUDY: The aim of the study was to evaluate the spectrum of AIDS-defining malignancies (ADMs) and non-AIDS-defining malignancies (NADMs) in HIV-infected patients in Poland. MATERIAL AND METHODS: A retrospective observational study was conducted among HIV-infected adult patients who developed a malignancy between 1995 and 2012 in a Polish cohort. Malignancies were divided into ADMs and NADMs. Non-AIDS-defining malignancies were further categorised as virus-related (NADMs-VR) and unrelated (NADMs-VUR). Epidemiological data was analysed according to demographic data, medical history, and HIV-related information. Results were analysed by OR, EPITools package parameters and Fisher's exact test. RESULTS: In this study 288 malignancies were discovered. The mean age at diagnosis was 41.25 years (IQR20-81); for ADMs 38.05 years, and for NADMs-VURs 46.42 years; 72.22% were male, 40.28% were co-infected with HCV. The risk behaviours were: 37.85% IDU, 33.33% MSM, and 24.31% heterosexual. Mean CD4+ at the diagnosis was 282 cells/mm(3) (for ADMs 232 and for NADMs-VUR 395). Average duration of HIV infection at diagnosis was 5.69 years. There were 159 (55.2%) ADMs and 129 (44.8%) NADMs, among whom 58 (44.96%) NADMs-VR and 71 (55.04%) NADMs-VUR. The most frequent malignancies were: NHL (n = 76; 26.39%), KS (n = 49; 17.01%), ICC (n = 34; 11.81%), HD (n = 23; 7.99%), lung cancer (n = 18; 6.25%) and HCC (n = 14; 4.86%). The amount of NADMs, NADMs-VURs in particular, is increasing at present. Male gender (OR = 1.889; 95% CI: 1.104–3.233; p = 0.024), advanced age: 50–60 years (OR = 3.022; 95% CI: 1.359–6.720; p = 0.01) and ≥ 60 years (OR = 15.111; 95% CI: 3.122–73.151; p < 0.001), longer duration of HIV-infection and successful HAART (OR = 2.769; 95% CI: 1.675–4.577; p = 0) were independent predictors of NADMs overall, respectively. CONCLUSIONS: In a Polish cohort NHL was the most frequent malignancy among ADMs, whereas HD was the most frequent among NADMs. Increased incidence of NADMs appearing in elderly men with longer duration of HIV-infection and with better virological and immunological control was confirmed. As HIV-infected individuals live longer, better screening strategies, especially for NADMs-VUR, are needed. The spectrum of cancer diagnoses in Poland currently does not appear dissimilar to that observed in other European populations

Meeting the WHO 90% target : antiretroviral treatment efficacy in Poland is associated with baseline clinical patient characteristics

Introduction: Modern combined antiretroviral therapies (cART) allow to effectively suppress HIV-1 viral load, with the 90% virologic success rate, meeting the WHO target in most clinical settings. The aim of this study was to analyse antiretroviral treatment efficacy in Poland and to identify variables associated with virologic suppression. Methods: Cross-sectional data on 5152 (56.92% of the countrywide treated at the time-point of analysis) patients on cART for more than six months with at least one HIV-RNA measurement in 2016 were collected from 14 Polish centres. Patients’ characteristics and treatment type-based outcomes were analysed for the virologic suppression thresholds of <50 and <200 HIV-RNA copies/ml. CART was categorized into two nucleos(t)ide (2NRTI) plus non-nucleoside reverse transcriptase (NNRTI) inhibitors, 2NRTI plus protease (PI) inhibitor, 2NRTI plus integrase (InI) inhibitor, nucleos(t)ide sparing PI/r+InI and three drug class regimens. For statistics Chi-square and U-Mann Whitney tests and adjusted multivariate logistic regression models were used. Results: Virologic suppression rates of <50 copies/mL were observed in 4672 (90.68%) and <200 copies/mL in 4934 (95.77%) individuals. In univariate analyses, for the suppression threshold <50 copies/mL higher efficacy was noted for 2NRTI+NNRTI-based combinations (94.73%) compared to 2NRTI+PI (89.93%), 2NRTI+InI (90.61%), nucleos(t)ide sparing PI/r+InI (82.02%) and three drug class regimens (74.49%) (p < 0.0001), with less pronounced but significant differences for the threshold of 200 copies/mL [2NRTI+NNRTI-97.61%, 2NRTI+PI-95.27%, 2NRTI+InI-96.61%, PI/r+InI- 95.51% and 86.22% for three drug class cART) (p < 0.0001). However, in multivariate model, virologic efficacy for viral load <50 copies/mL was similar across treatment groups with significant influence by history of AIDS [OR:1.48 (95%CI:1.01–2.17) if AIDS diagnosed, p = 0.046], viral load < 5 log copies/mL at care entry [OR:1.47 (95%CI:1.08–2.01), p = 0.016], baseline lymphocyte CD4 count ≥200 cells/µL [OR:1.72 (95%CI:1.04–2.78), p = 0.034] and negative HCV serology [OR:1.97 (95%CI:1.29–2.94), p = 0.002]. For viral load threshold <200 copies/mL higher likelihood of virologic success was only associated with baseline lymphocyte CD4 count ≥200 cells/µL [OR:2.08 (95%CI:1.01–4.35), p = 0.049] and negative HCV status [OR:2.84 (95%CI:1.52–5.26), p = 0.001]. Conclusions: Proportion of virologically suppressed patients is in line with WHO treatment target confirming successful application of antiretroviral treatment strategy in Poland. Virological suppression rates depend on baseline patient characteristics, which should guide individualized antiretroviral tre0atment decisions

Advances in Computational Social Science and Social Simulation

Aquesta conferència és la celebració conjunta de la "10th Artificial Economics Conference AE", la "10th Conference of the European Social Simulation Association ESSA" i la "1st Simulating the Past to Understand Human History SPUHH".Conferència organitzada pel Laboratory for Socio­-Historical Dynamics Simulation (LSDS-­UAB) de la Universitat Autònoma de Barcelona.Readers will find results of recent research on computational social science and social simulation economics, management, sociology,and history written by leading experts in the field. SOCIAL SIMULATION (former ESSA) conferences constitute annual events which serve as an international platform for the exchange of ideas and discussion of cutting edge research in the field of social simulations, both from the theoretical as well as applied perspective, and the 2014 edition benefits from the cross-fertilization of three different research communities into one single event. The volume consists of 122 articles, corresponding to most of the contributions to the conferences, in three different formats: short abstracts (presentation of work-in-progress research), posters (presentation of models and results), and full papers (presentation of social simulation research including results and discussion). The compilation is completed with indexing lists to help finding articles by title, author and thematic content. We are convinced that this book will serve interested readers as a useful compendium which presents in a nutshell the most recent advances at the frontiers of computational social sciences and social simulation researc

More for less : on consumer rationality and bargaining power on telecommunication markets

We analyse the large scale agent-based model of a prepaid telecommunication market with oligopolistic competition, heterogeneous calling patterns and different levels of agent rationality. We apply innovative implementation approach of utilizing high performance CUDA computing devices which allows us to consider population of up to 1 million consumers. We measure influence of a call graph structure, intra-family network choice coordination and agent rationality level on the market equilibrium. We discover that boundedly rational subscribers, who exploit simple decision heuristics to coordinate network choice within closed user groups, exert much stronger pressure on suppliers than fully rational ones. This leads to lower average calling costs, increased welfare and decreased monopolistic power of operators. We also observe asymmetry in operator margins and volume of on-net and off-net calls in accordance with empirical facts

Energy Productivity Potential of Offshore Wind in Poland and Cooperation with Onshore Wind Farm

Wind power is the leader in electricity production among the standing RES technologies, both in Poland and in Europe/World. In Poland, so far there are only onshore wind turbines. Their dynamic increase in installed capacity has been observed, especially between 2011 and 2017. This study analyzed the impact of offshore wind energy on the ability of the Polish power system to meet power demands. For this purpose, methods of statistical analysis (of existing onshore and planned offshore technologies) for the determination of wind turbine productivity based on wind speed components data from the ERA5 service were used. For onshore wind turbines, the value of the capacity factor CF(P) in Poland was 25.5% in 2021 and 30.1% in 2022. As a result of the simulation, it was calculated that for the planned offshore wind farms, the capacity factor CF(B) would be 55.6% under 2022 wind speed conditions. The 2022 peak load demands in the Polish system were also analyzed. The quantitative impact of installing 6 GW of offshore wind turbine capacity on the national power system was also identified

Comparison of Support Programs for the Development of Photovoltaics in Poland: My Electricity Program and the RES Auction System

Poland has great potential for the development of renewable energy sources. The implementation of support systems dedicated to renewable sources has resulted in the installation of over 10,500 MW of installed capacity. At present, with high electricity prices, stimulated by the costs of CO2 emissions and the costs of fuel purchase, renewable energy sources are of particular importance in the transformation of the Polish power industry. The RES auction system and the My Electricity Program contributed to the growth of entrepreneurship and the development of the economy. Energy consumers, from passive ones, have become active market participants—prosumers. The RES auction system alone contributed to the creation of approx. 5 GWp of installed capacity of photovoltaics (PV) sources in 2016–2021, while the My Electricity Program contributed to the creation of approx. 2 GWp of installed capacity in PV installations in 2019–2021. The aim of the study is to compare the economic and social costs of two photovoltaic development programs, My Electricity and the RES auction system, from the point of view of the country (in support distribution costs—subsidies) and investors, renewable energy installations operators and prosumers to which these programs are targeted, namely, individuals and enterprises

An investigation of longwall failure using 3D numerical modelling – A case study at a copper mine

It is well-known that the longwall mining method (with roof caving) is widely used in underground mining extraction for bedded deposits (e.g. coal) due to its numerous advantages. Generally, this method is not commonly applied for ore deposits such as copper deposit. In Poland, the longwall mining method has been tested for thin copper deposits at the Polkowice-Sieroszowice copper mine (KGHM). Various failure modes were observed during longwall operation in the 5A/1 panel. This paper aims to examine these occurred failures. To do so, an analysis has been conducted using 3D numerical modelling to investigate the failure mode and mechanism. Based on the 3D numerical modelling results with extensive in situ measurements, causes of failure are determined and practical recommendations for further copper longwall operations are presented