In this paper we determine the amortized computational complexity of the dynamic convex hull problem in the planar case. We present a data structure that maintains a finite set of n points in the plane under insertion and deletion of points in amortized O(log n) time per operation. The space usage of the data structure is O(n). The data structure supports extreme point queries in a given direction, tangent queries through a given point, and queries for the neighboring points on the convex hull in O(log n) time. The extreme point queries can be used to decide whether or not a given line intersects the convex hull, and the tangent queries to determine whether a given point is inside the convex hull. We give a lower bound on the amortized asymptotic time complexity that matches the performance of this data structure.

Our results formalize and confirm a folklore theorem about traditional bindingtime analysis, namely that CPS has a positive effect on binding times. What may be more surprising is that the benefit does not arise from a standard refinement of program analysis, as, for instance, duplicating continuations.

This dissertation shows how domain specific languages may be applied to the domain of interactive Web services to obtain flexible, safe, and e#cient solutions. We show how each of four key aspects of interactive Web services involving sessions, dynamic creation of HTML/XML documents, form field input validation, and concurrency control, may benefit from the design of a dedicated language.

Programming is at least as much about manipulating existing code as it is about writing new code. Existing code is modified, for example to make inefficient code run faster, or to accommodate for new features when reusing code; existing code is analyzed, for example to verify certain program properties, or to use the analysis information for code modifications. Semantics-based program manipulation addresses methods for program modifications and program analyses that are formally defined and therefore can be verified with respect to the programming-language semantics. This dissertation comprises four articles in the field of semantics-based techniques for program manipulation: three articles are about partial evaluation, a method for program specialization; the fourth article treats an approach to automatic cost analysis.

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Structures. January 1997. PhD thesis. x+121 pp. Torben Braner. An Axiomatic Approach to Adequacy. November 1996. Ph.D. thesis. 168 pp. 2 BRICS Dissertation Series, 1996--01 January 8, 2002 This document is also available as PostScript, DVI, References

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