Why do people contribute to open source software? : the motivations of the different contributors to OSS projects, and how their participation is characterized

Open source software has seen a significant evolution in the last few years. From relatively niche products and free alternative solutions to mass commercial software, OSS has been adopted by some of the largest companies in technology as a viable mean to create some of the most used programs and operating systems nowadays. The past research on this topic has approached the benefits of this perspective, the roles within the communities and the motivations of its contributors. However, there has not been research that has approached a detailed definition of the profiles within these communities, and how these contributors are motivated. In this research, we defined four profiles within the OSS communities, based on personality traits, as well as taking into account the reasons that lead them to choose the project in which they participate. Furthermore, we characterized these profiles of contributors from the nature of their contribution in OSS projects to demographics. Finally, we assessed the main motivations that drive each of these groups, finding that there are significant differences of motivations between the profiles, particularly in an intrinsic level. Finally, we assessed the difference between groups concerning reasons for contributors to increase their participation, and found, once again, that there are significant differences between groups in what would lead them to participate more. This research found that there is potential for organizations to select the contributors that are a better fit for their communities, and target their motivations and preferred incentives.O software de open source (OSS) tem experienciado uma evolução significativa nos últimos anos. De produtos de nicho e soluções grátis alternativas para software comercial distribuído em massa, OSS foi adotado por algumas das maiores empresas de tecnologia como um meio viável para criar alguns dos programas e sistemas operativos mais utilizados nos dias de hoje. A literatura existente sobre este tema abordou os benefícios desta perspetiva, os papéis dentro das comunidades e as motivações de seus contribuidores. No entanto, não há até à data, segundo nosso conhecimento, estudos que tenham abordado uma definição detalhada dos perfis dentro dessas comunidades e como esses contribuidores são motivados. No presente estudo, definimos quatro perfis dentro das comunidades OSS, com base em traços de personalidade, bem como tendo em conta as razões que os levam a escolher o projeto em que participam. Além disso, caracterizamos esses perfis de contribuidores, desde a natureza da sua contribuição em projetos de OSS até a dados demográficos. Foram também avaliadas as principais motivações de cada um desses grupos, concluindo que existem diferenças significativas de motivações entre os perfis, particularmente a um nível intrínseco. Finalmente, estudámos a diferença entre os grupos relativamente às razões que levariam os contribuidores a aumentar sua participação e verificámos, uma vez mais, que existem diferenças significativas entre os grupos. Esta pesquisa concluiu que existe potencial para as organizações de selecionar os contribuidores que se ajustam melhor às suas comunidades, e segmentar as suas motivações e incentivos preferenciais

Technological coaxial plasma accelerator

Plasma sources for accelerators intended for separation processes and surface treatment have been investigated. The conditions for the choice of system parameters, as well as plasma flux, injection system, and power source have been discussed. These parameters have been obtained experimentally. A conclusion about the role of metal erosion products of the electrodes has also been drawn.Исследуются плазменные источники-ускорители для процессов сепарации и обработки поверхностей. Обсуждаются условия выбора параметров системы, плазменного потока, системы напуска газа, источника питания. Экспериментально получены их параметры. Сделан вывод о роли металлических продуктов эрозии электродов.Досліджуються плазмові джерела прискорювачів для процесів сепарації та обробки поверхонь. Обговорюються умови вибору параметрів системи, плазмового потоку, системи напуску газа, джерела живлення. Експериментально одержані їх параметри. Зроблені висновки щодо металевих продуктів ерозії електродів

Modernization of the multipurpose accelerating system VGIK-1

The aim of VGIK-1 modernization is the possibility of metal surface processing by ion and electron irradiation, widening a range of applied energies and beam densities, vacuum condition control. This is reached by usage of two diodes, where one of them has isolated and defocussing magnetic system and another one has plasma emitter for extraction of ions and electrons. There is also the system of plasma parameters control. Vacuum system includes the cryogenic, diffusion and titanium sorbtion pumps and mass-spectrometric syste

Search for composite and exotic fermions at LEP 2

A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio

Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP

Promptly decaying lightest neutralinos and long-lived staus are searched for in the context of light gravitino scenarios. It is assumed that the stau is the next to lightest supersymmetric particle (NLSP) and that the lightest neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of the production of these particles is found. Hence, lower mass limits for both kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is found to be greater than 71.5 GeV/c^2. In the search for long-lived stau, masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10 to 150 \eVcc . Combining this search with the searches for stable heavy leptons and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc may be set for the stau mas