Irreversibility and Chaos in Active Particle Suspensions

Active matter has been the object of huge amount of research in recent years for its important fundamental and applicative properties. In this paper we investigate active suspensions of micro-swimmers through direct numerical simulation, so that no approximation is made at the continuous level other than the numerical one. We consider both pusher and puller organisms, with a spherical or ellipsoidal shape. We analyse the velocity and the characteristic scales for an homogeneous two-dimensional suspension and the effective viscosity under shear. We bring evidences that the complex features displayed are related to a spontaneous breaking of the time-reversal symmetry. We show that chaos is not a key ingredient, whereas a large enough number of interacting particles and a non-spherical shape are needed to break the symmetry and are therefore at the basis of the phenomenology. Our numerical study also shows that pullers display some collective motion, though with different characteristics from pushers

Exploratory literature review on free products : a structural topic model approach

Free products and services have increased tremendously in the last decade as a market ing technique and business strategy. We can observe this trend in the academic literature as well. In this exploratory literature review, we are interested in the different themes of this research area and how they have changed through time. We create a structural topic model (STM) to identify the underlying themes. An STM allows us to incorporate metadata into the model. This way, we can observe how the topics evolve depending on the publication year of the article. The study includes 279 academic papers from 1976 until 2022. We survey an increasing trend of themes situated in a digital world, especially for freemium products, and research concerning online consumer behavior. We identify two categories to classify free products; free products used as a marketing technique and free products as part of a business strategy.Os produtos e serviços gratuitos aumentaram tremendamente na última década como técnica de marketing e estratégia comercial. Podemos observar esta tendência também na literatura académica. Nesta revisão exploratória da literatura, estamos interessados nos di ferentes temas desta área de investigação e em como eles mudaram ao longo do tempo. Criamos um modelo temático estrutural (STM) para identificar os temas subjacentes. Um STM permite-nos incorporar metadados no modelo. Desta forma, podemos observar como os temas evoluem em função do ano de publicação do artigo. O estudo inclui 279 artigos académicos desde 1976 até 2022. Inquirimos uma tendência crescente de temas situa dos num mundo digital, especialmente para produtos "freemium", e investigação sobre o comportamento dos consumidores em linha. Identificamos duas categorias para classifi car produtos gratuitos; produtos gratuitos utilizados como técnica de marketing e produtos gratuitos como parte de uma estratégia empresarial

Big Sky Finance Company v. Avis and Archibald Title Insurance Agency, Lawyers Title Insurance Corporation, Fireman\u27s Fund Insurance Company, Title Pac, Inc., Jayson Cherry, William A. Avis, Robin Archibald : Brief of Appellee

Brief of Appelle

Strategic alignment of manufacturing processes in a Balanced Scorecard-based compensation plan: a theory illustration case

The present paper integrates the operations management and the management control literature in order to focus on the issue of strategic alignment in a BSC-based compensation plan. The specific objectives for this paper are twofold. First, the study offers a theoretical foundation for the thesis that alignment of manufacturing processes with business strategy will result in higher organizational performance. Second, a case study at a Belgian manufacturing division of a Danish corporate company shows that it is not possible to realize higher organizational performance when there is no strategic alignment of manufacturing processes

Overview of radio experiments for UHE cosmic particles detection

Radio-detection is a mature technique that has gained large momentum over the past decades. Its physical detection principle is mainly driven by the electromagnetic part of the shower, and is therefore not too sensitive to uncertainties on hadronic interactions. Furthermore its technical detection principle allows for a 100% duty cycle, and large surface coverage thanks to the low cost of antennas. Various detection methods of UHE particles now rely on the radio signal as main observable. For instance, ground based experiments such as AERA on the Pierre Auger Observatory or LOFAR detect the radio emission from air-showers induced by high-energy particles in the atmosphere; in-ice experiment such as ARA, IceCube, or ARIANNA benefits from a detection in denser media which reduces the interaction lengths; finally, balloon experiments such as ANITA allow for very sensitive UHE neutrino detection with only a few antennas. Radio-detection is now focused on building increasingly large-scale radio experiments to enhance the detector sensitivity and address the low fluxes at UHE. In this proceeding we give an overview of the past, current and future experiments for the detection of UHE cosmic particles using the radio technique in air (AERA, Auger-Prime, GRAND), in balloon (ANITA, PUEO) or in other media (IceCube-Gen2, BEACON, RNO-G).Comment: 12 pages, 8 figures, Rencontres de Moriond 2022: conference proceeding; section 4.2 and acknowkedgements update

A smooth extension method for transmission problems

In this work, we present a numerical method for the resolution of transmission problems with non-conformal meshes which preserves the optimal rates of convergence in space. The smooth extension method is a fictitious domain approach based on a control formulation stated as a minimization problem, that we prove to be equivalent to the initial transmission problem. Formulated as a minimization problem, the transmission problem can be solved with standard finite element function spaces and usual optimization algorithms. The method is applied to different transmission problems (Laplace, Stokes and a fluid-structure interaction problem) and compared to standard finite element methods

Research Note: ‘If I said I trust you, I would be lying’. Reflections and recommendations for conducting interviews with (violent) extremist prisoners

Over the past decade, the (violent) extremism, terrorism and countering violent extremism (CVE) research field is witnessing an increasing number of studies based on primary data collection. Despite this evolution, however, conducting face-to-face interviews with former or active (violent) extremists and terrorists still appears to be the exception rather than the rule. In addition, most evidence-based research often lacks methodological transparency on the researchers’ experiences, good practices, and the challenges faced during the different research phases (e.g., making contact with the respondents, the process of creating trust, challenges linked to the prison context). Therefore, the aim of this article is to provide academic researchers with insight into the potential challenges they may encounter when contacting and interviewing former or active (violent) extremist prisoners, and how to overcome them. The results are based on field experiences of a PhD research on the process toward (violent) extremism and terrorism in which qualitative in-depth interviews are conducted with (violent) extremist prisoners in Belgium. By providing reflections and recommendations based on this fieldwork, this article can be used as a guideline to improve and increase future primary data collection and the methodological transparency and reliability within terrorism and CVE research