System Issues in Multi-agent Simulation of Large Crowds

Crowd simulation is a complex and challenging domain. Crowds demonstrate many complex behaviours and are consequently difficult to model for realistic simulation systems. Analyzing crowd dynamics has been an active area of research and efforts have been made to develop models to explain crowd behaviour. In this paper we describe an agent based simulation of crowds, based on a continuous field force model. Our simulation can handle movement of crowds over complex terrains and we have been able to simulate scenarios like clogging of exits during emergency evacuation situations. The focus of this paper, however, is on the scalability issues for such a multi-agent based crowd simulation system. We believe that scalability is an important criterion for rescue simulation systems. To realistically model a disaster scenario for a large city, the system should ideally scale up to accommodate hundreds of thousands of agents. We discuss the attempts made so far to meet this challenge, and try to identify the architectural and system constraints that limit scalability. Thereafter we propose a novel technique which could be used to richly simulate huge crowds

Role of fiberoptic bronchoscopy in sputum smear negative suspected cases of pulmonary tuberculosis: a study conducted in Southern part of Rajasthan

Background: Sputum smear negative pulmonary tuberculosis is a common problem faced by clinicians. Fiberoptic bronchoscopy may be very useful in diagnosing these cases which have no sputum or whose sputum smear is negative for acid fast bacilli. Objective of the current study was to assess the role of fiberoptic bronchoscopy in sputum smear negative under NTEP and radiologically suspected cases of pulmonary tuberculosis.Methods: Clinico-radiological suspected cases of pulmonary tuberculosis patients in whom two sputum smear for acid fast bacilli by Ziehl Neelsen stain under NTEP was negative were included in the study. Fiberoptic bronchoscopy was performed in all these patients and samples taken were sent for investigations.Results: Fiberoptic bronchoscopy was performed in 250 patients of suspected pulmonary tuberculosis whose sputum for AFB smear was negative. Cough was the most predominant symptom. Radiologically, right side disease was more common and upper zone was most commonly involved and infiltrates were common radiological finding. During bronchoscopy, congestion and hyperaemia (36%) and mucopurulent/mucoid secretions (32%) was seen in maximum number of cases. BAL was positive in 200 patients (80%), post bronchoscopy sputum was positive in 70 cases (28%) and biopsy was positive in 12 patients out of 16 performed biopsies (75%). The total TB positive cases after combining all the methods were 215 making the overall diagnostic yield of 86%.Conclusions: Fiberoptic bronchoscopy and post bronchoscopy sputum can be very useful for diagnosing sputum for AFB smear negative but clinico-radiological suspected cases of pulmonary tuberculosis patients

A study of bronchial asthma in school going children in Southern part of Rajasthan

Background: Asthma is a chronic and common inflammatory disease involving mainly large airways of lungs. Childhood asthma is common chronic illness among school going children and is usually underdiagnosed and undertreated. The aim of the present study was to find out of the prevalence of Bronchial asthma in school going children of age group 6-12 years in southern part of Rajasthan (India), and its relation with gender, socio-economic status and heredity.Methods: A questionnaire-based study has been carried out in 1500 children of 6 to 12 years age group in four schools of Udaipur city (Rajasthan, India) with a response rate of 60.23% (904/1500).Results: The overall prevalence of asthma observed is 4.75% (43/904). The prevalence is higher among boys (5.55%) as compared to girls (3.75%). Further the prevalence is higher in upper (7.18%) and upper middle class (7.14%) children as compared to lower middle (4.84%) and upper lower class (2.01%) socioeconomic status. The children with positive family history of asthma also have higher prevalence (26.31%) of asthma.Conclusions: The prevalence of childhood asthma in Udaipur city is relatively lower and supports the already reported relation with gender, socioeconomic status and heredity.