Asymmetric periodic orbits in the photogravitational Copenhagen problem

AbstractIn this paper we study the Ox-asymmetric solutions of the planar photogravitational restricted three-body problem in the case of primaries with equal masses and equal values of the radiation pressure parameters. In particular, we are concerned with the families of asymmetric orbits which bifurcate from the well known families a, b, and c. Their evolution is examined via the numerical construction of series of the critical bifurcation points of a, b, and c with respect to the variation of the common radiation parameter q. We also present some illustrative cases of these families for several values of this parameter. In order to avoid the singularity due to binary collisions between the third body and one of the primaries, the equations of motion of the problem are regularized by using the Levi-Civita transformations

Linear Stability of Triangular Equilibrium Points in the Generalized Photogravitational Restricted Three Body Problem with Poynting-Robertson Drag

In this paper we have examined the linear stability of triangular equilibrium points in the generalised photogravitational restricted three body problem with Poynting-Robertson drag. We have found the position of triangular equilibrium points of our problem. The problem is generalised in the sense that smaller primary is supposed to be an oblate spheroid. The bigger primary is considered as radiating. The equations of motion are affected by radiation pressure force, oblateness and P-R drag. All classical results involving photogravitational and oblateness in restricted three body problem may be verified from this result. With the help of characteristic equation, we discussed the stability. Finally we conclude that triangular equilibrium points are unstable.Comment: accepted for publication in Journal of Dynamical Systems & Geometric Theories Vol. 4, Number 1 (2006

Linear Stability of Equilibrium Points in the Generalized Photogravitational Chermnykh's Problem

The equilibrium points and their linear stability has been discussed in the generalized photogravitational Chermnykh's problem. The bigger primary is being considered as a source of radiation and small primary as an oblate spheroid. The effect of radiation pressure has been discussed numerically. The collinear points are linearly unstable and triangular points are stable in the sense of Lyapunov stability provided $\mu< \mu_{Routh}=0.0385201$. The effect of gravitational potential from the belt is also examined. The mathematical properties of this system are different from the classical restricted three body problem

The Effect of Radiation Pressure on the Equilibrium Points in the Generalised Photogravitational Restricted Three Body Problem

The existence of equilibrium points and the effect of radiation pressure have been discussed numerically. The problem is generalized by considering bigger primary as a source of radiation and small primary as an oblate spheroid. We have also discussed the Poynting-Robertson(P-R) effect which is caused due to radiation pressure. It is found that the collinear points $L_1,L_2,L_3$ deviate from the axis joining the two primaries, while the triangular points $L_4,L_5$ are not symmetrical due to radiation pressure. We have seen that $L_1,L_2,L_3$ are linearly unstable while $L_4,L_5$ are conditionally stable in the sense of Lyapunov when P-R effect is not considered. We have found that the effect of radiation pressure reduces the linear stability zones while P-R effect induces an instability in the sense of Lyapunov

Towards an Ontology for Teamwork Enabled Services

Teamwork ability is a crucial aspect of humans, agents and other intelligent systems. This study is dedicated to the conceptual formal modeling of service teamworking by considering concepts defined within a vast range of models and theories of human and agent team development. We make the conceptual based modeling by using ontologies to define teams, roles, services and their modeling domains abstracting the most important concepts of team development whilst providing a decent level of formality and unambiguity. An ontology named TrEWSOnto is proposed as a model to assist the development process of teamwork enabled services in tandem with the representation of their composition process activity. This includes (i) the definition of concepts that are used to improve the teamwork ability of peer services, (ii) the description of the main concepts are used for the role modeling composition, and (iii) the description of situations that teamwork roles should monitor to catch potential "unhealthy"behavior happen during the service activity in order to run proactively and avoid obstacles or collisions. The result is a structure of five ontology sections together forming a representation for TeamwoRk Enabled Web (TrEW) Services and the environment they live. © 2020 ACM

Asymptotic and periodic motion around collinear equilibria in Chermnykh's problem

In this paper we study the asymptotic motion to the collinear equilibrium points of Chermnykh's problem. More specifically, we give three kinds of non-symmetric doubly-asymptotic solutions emanating from L1 and L3. We also show that these solutions are closely connected to the families of periodic orbits generated around these equilibria

A Framework for developing Teamwork Enabled Services in Smart City Domains

Services that collaborate alongside other services or systems for performing tasks, need to be aware of either predetermined or other abrupt and unexpected behaviors in other to adapt theirs. The service behaviors we consider are performed in smart city domains which are dynamic environments where continuously new services appear, that usually have a large variation in the way they perform the same task. We use roles having teamwork behavior to represent the composition procedure in such domains, and we model the team of services through the individual behavior of each participant as well as their group goal. In this paper, we present a framework, which consists of the approach and IT system in order to serve the choreography between a large number of heterogeneous services so as to achieve a seamless and cooperative environment suitable for a smart city. This enables composite city services to adapt their behavior during execution and themselves intervene from inside the team if a possible unexpected behavior happens during the service activity, in order to run proactively and avoid obstacles or collisions. A scenario from a smart city domain illustrates that, services having different teamwork abilities are composed to a new one which inherits teamwork features and combines them to something novel. © 2021 ACM

Nexus Services in Smart City Ecosystems

According to market research, the number of smart cities is increasing rapidly. Information and communication technologies (ICT) provide the smart infrastructure that is the foundation for all the key themes related to a smart city, such as smart economy, smart governance, smart mobility, smart health, smart buildings, and smart water. As such, a smart city is constituted of various infrastructure components that form a complex system of systems, which is essential to collaborate effectively. Services play a central role in this vision of smart cities, as they are used as building blocks for effective collaboration, i.e., to achieve interoperability between heterogeneous parties and independence from the underlying infrastructure. In order to cope with the problem of complexity and the scalability in smart cities’ systems, a solution is to provide autonomous, collaborating services that have situation awareness and are able to adapt dynamically to the changing needs of the environment forming a nexus of services. In this research, we propose a nexus model for smart cities’ services collaboration by using the role modeling approach enhanced by the introduction of service teamwork roles. The teamwork roles definition is inspired both by human and agent team working models. We determine the dominant teamwork roles that prevail during service group cooperation, where the main goal of each role is to intervene and “act as a connector” during collaboration to keep the team of component services consistent with the goal of the group–team. The teamwork functionality is applied through the introduction of a new layer in the architecture of smart cities and is exploited to overcome some of the aforementioned problems. A case study that presents how teamwork roles could affect and benefit the service collaboration in a smart city environment is also provided. © 2020, Springer Science+Business Media, LLC, part of Springer Nature