429 research outputs found

    Role of opinion sharing on the emergency evacuation dynamics

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    Emergency evacuation is a critical research topic and any improvement to the existing evacuation models will help in improving the safety of the evacuees. Currently, there are evacuation models that have either an accurate movement model or a sophisticated decision model. Individuals in a crowd tend to share and propagate their opinion. This opinion sharing part is either implicitly modeled or entirely overlooked in most of the existing models. Thus, one of the overarching goal of this research is to the study the effect of opinion evolution through an evacuating crowd. First, the opinion evolution in a crowd was modeled mathematically. Next, the results from the analytical model were validated with a simulation model having a simple motion model. To improve the fidelity of the evacuation model, a more realistic movement and decision model were incorporated and the effect of opinion sharing on the evacuation dynamics was studied extensively. Further, individuals with strong inclination towards particular route were introduced and their effect on overall efficiency was studied. Current evacuation guidance algorithms focuses on efficient crowd evacuation. The method of guidance delivery is generally overlooked. This important gap in guidance delivery is addressed next. Additionally, a virtual reality based immersive experiment is designed to study factors affecting individuals\u27 decision making during emergency evacuation

    Multi Objective Optimization of classification rules using Cultural Algorithms

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    AbstractClassification rule mining is the most sought out by users since they represent highly comprehensible form of knowledge. The rules are evaluated based on objective and subjective metrics. The user must be able to specify the properties of the rules. The rules discovered must have some of these properties to render them useful. These properties may be conflicting. Hence discovery of rules with specific properties is a multi objective optimization problem. Cultural Algorithm (CA) which derives from social structures, and which incorporates evolutionary systems and agents, and uses five knowledge sources (KS's) for the evolution process better suits the need for solving multi objective optimization problem. In the current study a cultural algorithm for classification rule mining is proposed for multi objective optimization of rules

    Some new mathematical features in cascade theory

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    AbstractThe fluctuation problem in cascade theory is viewed from the standpoint of the invariant imbedding method of Bellman et al. [1]. The correlation functions that are used in the description of the electromagnetic cascades are shown to obey a simple system of two component vector differential equations. The advantage of the present method over the conventional approach of writing down Kolmogorov forward equations for these functions lies in that we encounter 2 × 2 matrices of a particular type only. In view of the simplicity of the structure it is possible to generalize the equations to correlation functions of arbitrary order. The reduction in dimension from 2n × 2n matrices to only 2 × 2 matrices which may, at first sight, appear perplexing is due to the fact that each of the 2n elements that appear in the single system of differential equations, corresponding to the two different initial conditions, can be obtained by considering 2n disjoint systems of two component vector equations. The imbedding technique is also used to arrive at the independent differential equations satisfied by sequent product densities that are encountered in more comprehensive description of electromagnetic cascades

    Stranded in isolation: structural role of isolated extended strands in proteins

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    Reasons for the formation of extended-strands (E-strands) in proteins are often associated with the formation of β -sheets. However E-strands, not part of β-sheets, commonly occur in proteins. This raises questions about the structural role and stability of such isolated E-strands. Using a dataset of 250 largely non-homologous and high-resolution (<2 Å) crystal structures of proteins, we have identified 518 isolated E-strands from 187 proteins. The two most distinguishing features of isolated E-strands from β-strands in β-sheets are the high preponderance of prolyl residues occuring in isolated E-strands and their high exposure to the surroundings. Removal of regions with polyproline conformation from the dataset did not significantly reduce the propensity of prolyl residues to occur in isolated E-strands. Isolated E-strands are often characterized by their main-chain amide and carbonyl groups involved in hydrogen bonding with polar side chains or water. They are often flanked by irregular loop structures and are less well conserved, than β-sheet forming β-strands, among homologous protein structures. It is suggested that isolated β-strands have many characteristics of loop segments but with repetitive (φ,ψ) values falling within the β-region of the Ramachandran map

    MULTICAST OPERATIONS, ADMINISTRATION, AND MANAGEMENT (OAM) TECHNIQUES UTILIZING PROTOCOL INDEPENDENT MULTICAST (PIM) FLOODING MECHANISMS

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    Multicast networks are often complex and to provide a visualization of traffic flows within a multicast network often involves the full knowledge of a distribution tree for the network. Further, isolating problems within a multicast network can involve tracing of multiple nodes across the distribution tree. Techniques presented provide efficient multicast tree discovery through Protocol Independent Multicast (PIM) flooding mechanisms, which can be further used to facilitate network visualizations and fault isolation within a network

    Exploring anti-malarial potential of FDA approved drugs: an in silico approach

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    Background: The critically important issue on emergence of drug-resistant malarial parasites is compounded by cross resistance, where resistance to one drug confers resistance to other chemically similar drugs or those that share mode of action. This aspect requires discovery of new anti-malarial compounds or formulation of new combination therapy. The current study attempts to contribute towards accelerating anti-malarial drug development efforts, by exploring the potential of existing FDA-approved drugs to target proteins of Plasmodium falciparum. Methods: Using comparative sequence and structure analyses, FDA-approved drugs, originally developed against other pathogens, were identified as potential repurpose-able candidates against P. falciparum. The rationale behind the undertaken approach is the likeliness of small molecules to bind to homologous targets. Such a study of evolutionary relationships between established targets and P. falciparum proteins aided in identification of approved drug candidates that can be explored for their anti-malarial potential. Results: Seventy-one FDA-approved drugs were identified that could be repurposed against P. falciparum. A total of 89 potential targets were recognized, of which about 70 are known to participate in parasite housekeeping machinery, protein biosynthesis, metabolic pathways and cell growth and differentiation, which can be prioritized for chemotherapeutic interventions. An additional aspect of prioritization of predicted repurpose-able drugs has been explored on the basis of ability of the drugs to permeate cell membranes, i.e., lipophilicity, since the parasite resides within a parasitophorous vacuole, within the erythrocyte, during the blood stages of infection. Based on this consideration, 46 of 71 FDA-approved drugs have been identified as feasible repurpose-able candidates against P. falciparum, and form a first-line for laboratory investigations. At least five of the drugs identified in the current analysis correspond to existing antibacterial agents already under use as repurposed anti-malarial agents. Conclusions: The drug-target associations predicted, primarily by taking advantage of evolutionary information, provide a valuable resource of attractive and feasible candidate drugs that can be readily taken through further stages of anti-malarial drug development pipeline
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