Dennis G. Kafura

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Structured design methodologies provide a disciplined and organized guide to the construction of software systems. However, while the methodology structures and documents the points at which design decisions are made, it does not provide a specific, quantitative basis for making these decisions. Typically, the designers' only guidelines are qualitative,(More)
Authorization systems today are increasingly complex. They span domains of administration, rely on many different authentication sources, and manage permissions that can be as complex as the system itself. Worse still, while there are many standards that define authentication mechanisms, the standards that address authorization are less well defined and(More)
Many grid usage scenarios depend on small, dynamic working groups for which the ability to establish transient collaboration with little or no intervention from resource administrators is a key requirement. The system developed, PRIMA, focuses on the issues of management and enforcement of fine-grained privileges. Dynamic account creation and leasing as(More)
This paper reports on a modest study which relates seven different software complexity metrics to the experience of maintenance activities performed on a medium size software system. Three different versions of the system that evolved over a period of three years were analyzed in this study. A major revision of the system, while still in its design phase,(More)
We introduce the Symphony framework, a software abstraction layer that can sit on top of grid systems. Symphony provides a unified API for grid application developers and offers a graphical user interface for rapid collaborative development and deployment of grid applications and problem solving environments through compositional modeling following the(More)
<italic>This paper considers the garbage collection of concurrent objects for which it is necessary to know not only &#8220;reachability,&#8221; the usual criterion for reclaiming data, but also the &#8220;state&#8221; (active or blocked) of the object. For the actor model, a more comprehensive definition than previously available is given for reclaimable(More)
PRIMA, a system for PRIvilege Management and Authorization, provides enhanced Grid security services. The requirements for these services are derived from usage scenarios and supported by a survey of Grid users. The requirements for added flexibility, increased expressiveness, and more precise enforcement are met by a combination of three mechanisms: (1)(More)