8 research outputs found
Stochastics and Statistics Dynamic shortest path in stochastic dynamic networks: Ship routing problem
In this paper, we apply the stochastic dynamic programming to find the dynamic shortest path from the source node to the sink node in stochastic dynamic networks, in which the arc lengths are independent random variables with exponential distributions. In each node there is an environmental variable, which evolves in accordance with a continuous time Markovprocess. The parameter of the exponential distribution of the transition time of each arc is also a function of the state of the environmental variable of its initiative node. Upon arriving at each node, we can move toward the sink node through the best outgoing arc or wait. At the beginning, it is assumed that upon arriving at each node, we know the state of its environmental variable and also the states of the environmental variables of its adjacent nodes. Then we extend this assumption such that upon arriving at each node, we know the states of the environmental variables of all nodes. In the ship routing problem, which we focus in this paper, the environmental variables of all nodes are known, but it is shown that the complexity of the algorithm becomes exponential in this case
An Intervention for the Promotion of Supervisor's Incidents Reporting Process: the Case of a Steel Company
The analysis of incidents is one way of increasing safety in workplaces. In this approach, the process of preparing exact and scientific report is a critical step. The aim of this paper was to describe an intervention supporting the improvement of supervisors' participation to report all occurred incidents. In this study, Future Workshop method was used with 44 supervisors in TAB Steel Company, Tabriz, Iran. In each subject, 11 supervisors were participated in four small groups, which they normally worked. In the Critique phase, the 4 teams reported 126 problems in the incident report process. During the fantasy phase, the teams produced 727 suggestions to solve the problems. Then, the supervisors made decisions on 35 commitments to change their incident reporting behaviors. Finally, in the implementation phase the number of reported incidents increased by 79.4% during the 1-year follow-up period. The discussion method used in Japan, Finland, and Sweden was also successfully implemented in Iran, and the process raised a great number of problems and suggestions related to supervisor's incident reporting process. Creating and maintaining the proper communicational canals among supervisors and the managers of safety and health unit are the suggestions, which have been presented to increase the amount of partnership
CIRED Workshop -Lisbon E EV VA AL LU UA AT TI IO ON N A AN ND D E ER RR RO OR R M MI IN NI IM MI IZ ZA AT TI IO ON N O OF F D DY YN NA AM MI IC C S SH HO OR RT T T TI IM ME E L LO OA AD D F FO OR RE EC CA AS ST TI IN NG G M MO OD DE EL L W WI IT TH H C CO
ABSTRACT Short time load forecasting (STLF) is a pivotal concept in energy marketin