Shahid Jabbar

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To analyze larger models for explicit-state model checking, directed model checking applies error-guided search, external model checking uses secondary storage media, and distributed model checking exploits parallel exploration on multiple processors. In this paper we propose an external, distributed and directed on-the-fly model checking algorithm to check(More)
This paper provides a generic approach for map generation based on Global Positioning System (GPS) traces especially for unknown terrains. The system uses AI algorithms to infer the road geometry. Given a set of GPS traces, this input is refined by filtering and partitioning algorithms. For constructing the graph, clustering algorithms are applied that(More)
In this paper we study External A*, a variant of the conventional (internal) A* algorithm that makes use of external memory, e.g., a hard disk. The approach applies to implicit, undirected, unweighted state space problem graphs with consistent estimates. It combines all three aspects of best-first search, frontier search and delayed duplicate detection and(More)
Petri nets are fundamental to the analysis of distributed systems especially infinite-state systems. Finding a particular marking corresponding to a property violation in Petri nets can be reduced to exploring a state space induced by the set of reachable markings. Typical exploration(reachability analysis) approaches are undirected and do not take into(More)
Graphs are suitable modeling formalisms for software and hardware systems involving aspects such as communication, object orientation, concurrency, mobility and distribution. State spaces of such systems can be represented by graph transition systems, which are basically transition systems whose states and transitions represent graphs and graph morphisms.(More)
Directed model checking has proved itself to be a useful technique in reducing the state space of the problem graph. But still, its potential is limited by the available memory. This problem can be circumvented by the use of secondary storage devices to store the state space. This paper discusses directed best-first search to enhance error detection(More)
This paper provides a novel approach for optimal route planning by making efficient use of the underlying geometrical structure. It combines classical artificial intelligence exploration with computational geometry. Given a set of global positioning system (GPS) trajectories, the input is refined by geometric filtering and rounding algorithms. For(More)