Thermal stability of a special class of black hole solutions in F(R) gravity

In this paper, we work on the topological Lifshitz-like black hole solutions of a special class of vacuum $F(R)-$gravity that are static and spherically symmetric. We investigate geometric and thermodynamic properties of the solutions with due respect to the validity of the first law of thermodynamics. We examine the van der Waals like behavior for asymptotically AdS solutions with spherical horizon by studying the $P-v$, $G-T$ and $C_{Q,P}-r_{+}$ diagrams and find a consistent result. We also investigate the same behavior for hyperbolic horizon and interestingly find that the system under study can experience a phase transition with negative temperature.Comment: 14 pages with 7 captioned figures. Some additional notes are added. Accepted in EPJ

Causal Event Networks: Cognition, Complexity and Physical Laws

Information flow framed in a computational and complexity context is relevant to the understanding of cognitive processes and awareness. In this paper, we begin with analyzing an information theory framework developed in recent years under Information and Integration Theory (IIT) based on interactions among partitions of cognitive information sets. We discuss the scope and limitations of these ideas, introducing a related measure for partitioning information sets. We introduce a set of postulates describing cognition as a partially ordered set of events in space and time. We consider the relevant sequential and concurrent computational concepts in an idealized minimal cognitive device. The concept of fundamental cognitive chain formalizes temporal limits of cognition.Comment: 31 page

A model for achieving urban resiliency imaginary and explaining its relation with poverty

In order to reduce the risks of disasters, we need to establish theories to make seemingly disordered events, as logical phenomena. In fact, theory is like a map for reducing, answering and recovering from disasters. This subject is by the way, an exception because theory needs to be verified based on its immediate usage. This is a kind of necessity based on which problems of disasters, immediate response and reduction of risks must be answered so we cannot just make the theory and wish for it to become practical some day in future. Resilience in Urban and Regional Studies discussions is in search of special local properties that decrease vulnerability of urban areas. This is rooted in disaster confrontation studies so notion of resilience has more main limitation in answering the social-economic challenges. One of the most important challenges is confronting with poverty notion. Poverty, on one hand, reduces resilience because of increasing vulnerability, and on the other hand, poor locals regenerate vulnerable environments due to their high social correlations.The present study aims at investigating and analysis of theoretical and practical features in addition to recognized the dimensions of these two notions and their relation, plus extracting the main common concepts and indices of the relationship. Findings of the study show that governance concepts, social capital, social learning, social participation, institutionalism and vulnerability are among the intermediate rings in defining the relationship between poverty and resilience.Keywords: notion, resilience, poverty, vulnerability, disaster

A new ductile moment-resisting connection for precast concrete frames in seismic regions: An experimental investigation

A new ductile moment-resisting beam–column connection is developed for precast reinforced concrete (RC) frames in high seismic zones. The proposed connection provides good structural integrity in the connections and can reduce construction time by eliminating the need for formworks and welding, and minimizing cast-in-place concrete volume. A series of cyclic loading tests were carried out on six full-scale interior and exterior precast connections and two monolithic connections, all designed for use in high seismic zones. Test variables included the type of stirrups (open and closed) and the stirrup spacing in the beam connection zone. Test specimens were subjected to a constant axial load and a reverse cyclic loading based on a given displacement history. Flexural strength, ductility, strength degradation and energy dissipation capacity of the precast and monolithic connections are compared. The proposed interior and exterior moment-resisting connections proved to be efficient at improving the seismic performance of precast concrete frames in high seismic zones. While the precast connections provided adequate flexural strength, strength degradation and drift capacity, they exhibited considerably higher ductility and energy dissipation compared to similar monolithic specimens

Joint Inference of Structure and Diffusion in Partially Observed Social Networks

Access to complete data in large scale networks is often infeasible. Therefore, the problem of missing data is a crucial and unavoidable issue in analysis and modeling of real-world social networks. However, most of the research on different aspects of social networks do not consider this limitation. One effective way to solve this problem is to recover the missing data as a pre-processing step. The present paper tries to infer the unobserved data from both diffusion network and network structure by learning a model from the partially observed data. We develop a probabilistic generative model called "DiffStru" to jointly discover the hidden links of network structure and the omitted diffusion activities. The interrelations among links of nodes and cascade processes are utilized in the proposed method via learning coupled low dimensional latent factors. In addition to inferring the unseen data, the learned latent factors may also help network classification problems such as community detection. Simulation results on synthetic and real-world datasets show the excellent performance of the proposed method in terms of link prediction and discovering the identity and infection time of invisible social behaviors

On Franklin’s relativistic rotational transformation and its modification

Unlike the Lorentz transformation which replaces the Galilean transformation among inertial frames at high relative velocities, there seems to be no such a consensus in the case of coordinate transformation between inertial frames and uniformly rotating ones. There have been some attempts to generalize the Galilean rotational transformation to high rotational velocities. Here we introduce a modified version of one of these transformations proposed by Philip Franklin in 1922. The modified version is shown to resolve some of the drawbacks of the Franklin transformation, specially with respect to the corresponding spacetime metric in the rotating frame. This new transformation introduces non-inertial eccentric observers on a uniformly rotating disk and the corresponding metric in the rotating frame is shown to be consistent with the one obtained through Galilean rotational transformation for points close to the rotation axis. Employing the threading formulation of spacetime decomposition, spatial distances and time intervals in the spacetime metric of a rotating observer's frame are also discussed.Comment: 30 pages, 2 figures, replaced with the published versio

Evaluation of genetic diversity of Iranian grapevine accessions using microsatellite markers

Research Note