Software Configuration Management (SCM) is a concept of trying to group the changing artifacts of software development to try to manage the complexity of modern day software. This paper provides a roadmap for improving the SCM support process based on a meta-model. I developed a model that defines key practice...
Watering a lawn involves several factors such as laying out the sprinklers and valves, trenching, laying pipes, cables, etc. The primary goal is to ensure uniform watering subject to various constraints. We present some abstract problems involving sprinkler layout and some solutions with theoretical worst case bounds on their performance....
The Sacagawea testbed has been designed to support testing and development of decision making models, and associated uncertainty management techniques, that are appropriate under real-time problem solving constraints. Conceptually, it provides a simulated temporal and spatial environment, the latter consisting of a terrain grid of elevation and tree cover data,...
Performance of a reliable storage subsystem for a centralized database system was studied by simulation. The reliable storage subsystem studied consists of three redundant disk units that are updated one at a time from a consistent database state to another consistent database state, Thus, even if a central processor and/or...
An execution of a database system is considered correct if its net effect is as if transactions were executed serially, and such an execution is called serializable. In this short paper we show that the serializability test problem can be reduced to a simple pebbling problem. Our characterization is intuitive...
A theory for resiliency control of distributed database systems is developed, and schemes that preserve the consistent global database state in the presence of site crashes and message link failures are discussed. The schemes can at least theoretically be paired with any concurrency control scheme that produces y-serializable executions. Further,...
It is highly desirable for a distributed database system to achieve logically continuous operation even if some sites or message links fail. In this paper, we describe a scheme that can automatically reconfigure a fully-replicated distributed database system upon subsystem failures. The scheme can tolerate total failures of some sites....
A typical database system maintains target data, which contain information useful for users, and access path data, which facilitate faster accesses to target data. Further, most large database systems support concurrent processing of multiple transactions. For a static database system model, where units of concurrency control are not dynamically created...
In this short paper, we present an implementation method for a distributed commit/ termination protocol for a distributed database system. The protocol, which handles both commit and termination processing of distributed transactions, is represented by communicating Moore machines. Several advantages of our approach are discussed.
A concurrency and resiliency control scheme for a distributed database system with replicated data is discussed. The scheme, true-copy token scheme, uses true-copy tokens in order to designate the physical data copies (true copies) that can be identified with the current logical data that are globally unique, and then it...
ELGDF (Extended Large Grain Data Flow) is a design language that allows representation of a wide variety of parallel programs. The syntax is graphical and hierarchical to allow construction and viewing of realistically sized programs. ELGDF language facilitates describing parallel programs in a natural way for both shared memory model...
Test incorporations are program transformations that improve the performance of generate-and-test procedures by moving information out of the "test" and into the "generator." The test information is said to be "incorporated" into the generator so that items produced by the generator are guaranteed to satisfy the incorporated test. This article...
A tour of a graph (digraph, or sequential machine) is a sequence of nodes from the graph such that each node appears at least once and two nodes are adjacent in the sequence only if they are adjacent in the graph. Finding the shortest tour. of a graph is known...
A complete approach to uncertainty management requires support for interactive and incremental problem formulation, inference, hypothesis ranking, and decision making. In addition, computational models must allow for time and resource bounds. Current approaches to uncertainty management concentrate primarily on inference, provide little or no support for the larger issues in...
In this paper we will describe two known strategies for static processors allocation in an n-cube multiprocessor, namely the buddy system strategy and the gray code strategy and then propose a new strategy that outperforms the first by (n-k+1) and the second by (n-k+1)/2 in cube recognition. Furthermore, our strategy...
One of the most popular topologies is the hypercube, that has n = 2ᵏ processors, numbered 0 to 2ᵏ -1 and connected in such a way that there is a link between any two if and only if they differ in one bit. Its popularity is due to the fact...