Cutoff time based on generalized divergence measure

The cutoff phenomenon in the simulated methods has been widely investigated in recent years. An important question is to detect the stopping time after which one can obtain the convergence to equilibrium of an interesting Markov chain. We propose in this paper, a method for evaluating the cutoff instant using appropriate stopping times such as those found in [Lachaud, B. 2005. Cutoff and hitting times for a sample of Ornstein-Uhlenbeck processes and its everage, J. Appl. Probab. 42 (4), 1069-1080]. We give the conditions under which a Markov process has a cutoff time, in the sense of the generalized divergence measure. For illustration, we evaluate the effectiveness of our method on the Ornstein-Uhlenbeck process.

RAINWATER MANAGEMENT PROBLEMS IN CITIES IN DEVELOPING COUNTRIES: THE CASE OF THE MUNICIPALITY OF ZIGUINCHOR, SENEGAL

International audienceSenegalese cities are experiencing very rapid growth in terms of both spatial and demographic development, which has an impact on the management of runoff water, which is increasingly a major concern of authorities and urban populations. In these cities, public sanitation infrastructure is insufficient and unevenly distributed in urban space. The objective of this study is to characterize the problem of rainwater management in the city of Ziguinchor (southern Senegal). The methodology is based on an administration, a questionnaire submitted to 288 heads of households, and an interview guide with 13 actors who stand out in the environmental management component at the local level. The results obtained attest to a real problem of sanitation of rainwater managed in precarious conditions due to the lack of infrastructure and water management methods used by households. The infrastructural problem is a factor in the poor management of rainwater in Ziguinchor, while rainwater drainage practices do not protect the living environment of the populations. In the city of Ziguinchor, the main strategies adopted in the face of the sanitation network deficit are based on backfilling, the laying of sandbags and stones, evacuation through buckets