6,128 research outputs found
The laws of war and cyberspace: on the need for a treaty concerning cyber conflict
This report examines the militarization of cyberspace and considers ways to prevent the Internet from turning into a battlefield. Cyberspace is a domain of warfare unlike all others: it is primarily informational in nature, accessible electronically without the need for spatial proximity, and acts as a global data and communication highway. These properties have given rise to highly unusual patterns of continuous, low-intensity clandestine cyber conflict. The existing Laws of War, which apply to cyberspace as a matter of doctrine, are ill-equipped to deal with this. The community of states must negotiate a treaty on cyberwar, institutionalise cross-border law enforcement cooperation of cybercriminals, and place statesponsored digital espionage within the World Trade Organisation’s remit to arbitrate anti-competition disputes. Absent these steps, the Internet will become increasingly militarised, international cybercrime will continue to elude serious prosecution efforts, and the web’s utility for commercial and civilian purposes will degrade over time
A numerical study on active control for tiltrotor whirl flutter stability augmentation
The use of active control to augment whirl flutter stability of tiltrotor aircraft is studied by means of a multibody simulation. The numerical model is based on a 1/5 scale semi-span aeroelastic wind tunnel model of a generic tiltrotor concept and possesses a gimballed, stiff-in-plane rotor that is windmilling. A single-input single-output controller and two types of multi-input multi-output algorithms, Linear Quadratic Gaussian Control and Generalized Predictive Control, are studied. They are using measured wing deflections in order to calculate appropriate swashplate input. Results on the closed-loop behavior of three wing and two gimbal natural modes are given. Robustness analyses with respect to major parameters like wing natural frequencies or structural damping are also briefly discussed. The rotor shear force is shown in the uncontrolled condition and in presence of a controller in order to illustrate the whirl flutter mechanism. The single-input single-output controller yielded substantial gain in stability and turned out to be most suitable for industrial application, whereas the Linear Quadratic Gaussian Regulator yielded even higher damping and still had good robustness characteristics
Understanding the Why, What, and How of Theories in IS Research
Researchers have emphasized theory’s pivotal importance in the information systems (IS) discipline since its inception. As in many science disciplines, IS scholars’ ability to understand and contribute to theory is an important qualification in research practice. As a discipline, we require solid foundations for why we engage with theory, what theory is for us, and how we work with theory. We synthesize and reflect on the debates on theories and theorizing in the IS discipline. In doing so, we inform (particularly new) authors about the current state of the IS discipline’s debate on theory and theorizing and help them identify opportunities in theorizing to put theory to work. We do not intend to advocate or cement that status quo we portray but rather, through informing the community about it, to support early efforts to further develop and move beyond the current state of the debate on theory and theorizing in IS research
Intestinal macrophages: differentiation and involvement in intestinal immunopathologies
Intestinal macrophages, preferentially located in the subepithelial lamina propria, represent the largest pool of tissue macrophages in humans. As an adaptation to the local antigen- and bacteria-rich environment, intestinal macrophages exhibit several distinct phenotypic and functional characteristics. Notably, microbe-associated molecular pattern receptors, including the lipopolysaccharide (LPS) receptors CD14 and TLR4, and also the Fc receptors for IgA and IgG are absent on most intestinal macrophages under homeostatic conditions. Moreover, while macrophages in the intestinal mucosa are refractory to the induction of proinflammatory cytokine secretion, they still display potent phagocytic activity. These adaptations allow intestinal macrophages to comply with their main task, i.e., the efficient removal of microbes while maintaining local tissue homeostasis. In this paper, we review recent findings on the functional differentiation of monocyte subsets into distinct macrophage populations and on the phenotypic and functional adaptations that have evolved in intestinal macrophages in response to their antigen-rich environment. Furthermore, the involvement of intestinal macrophages in the pathogenesis of celiac disease and inflammatory bowel diseases is discusse
Accumulating Project Management Knowledge Using Process Theory
Process theory has become an important mechanism for the accumulation of knowledge in a number of disciplines. In contrast with variance theory, which focuses on co-variation of dependent and independent variables, process theory focuses on sequences of activities, their duration and the intervals between them, as they lead to particular outcomes. For example, rather than focusing on what properties successful projects have in common, process theory focuses on what sequences of activities lead to successful projects. Thus process theory is a powerful companion to variance theory, particularly relevant to project management knowledge accumulation. However, process theory itself and methods of developing process theories are still in a nascent stage. We present a 5-level model that specifies different formulations of process theory, explaining how it can be applied and leveraged to accumulate knowledge, specifically within project management research. We conclude by considering future possibilities and challenges for process theory in project management research
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