Let s be a string whose symbols are solely available through access(i), a read-only operation that probes s and returns the symbol at position i in s. Many compressed data structures for strings, trees, and graphs, require two kinds of queries on s: select(c, j), returning the position in s containing the jth occurrence of c, and rank(c, p), counting how many occurrences of c are found in the f...

Current workflow technology offers rich features to manage and enact business processes. In principle, the technology enables actors to cooperate in the execution of business processes regardless of their geographical location. Furthermore, the technology is considered as an efficient means to reduce processing times. In this paper, we evaluate the effects on the performance of a workflow proce...

State-of-the-art data analysis in production allows engineers to characterize reservoirs using production data. This saves companies large sums that should otherwise be spend on well testing and reservoir simulation and modeling. There are two shortcomings with today’s production data analysis: It needs bottom-hole or well-head pressure data in addition to data for rating reservoirs’ characteri...