Gail E. Kaiser

An information retrieval approach for automatically constructing software libraries

A technology for automatically assembling large software libraries which promote software reuse by helping the user locate the components closest to her/his needs is described. Software libraries are automatically assembled from a set of unorganized components by using information retrieval techniques. The construction of the library is done in two steps. First, attributes are automatically extracted from natural language documentation by using an indexing scheme based on the notions of lexical affinities and quantity of information. Then a hierarchy for browsing is automatically generated using a clustering technique which draws only on the information provided by the attributes. Due to the free-text indexing scheme, tools following this approach can accept free-style natural language queries. >

Concurrency control in advanced database applications

Concurrency control has been thoroughly studied in the context of traditional database applications such as banking and airline reservations systems. There are relatively few studies, however, that address the concurrency control issues of advanced database applications such as CAD/CAM and software development environments. The concurrency control requirements in such applications are different from those in conventional database applications; in particular, there is a need to support non-serializable cooperation among users whose transactions are long-lived and interactive, and to integrate concurrency control mechanisms with version and configuration control. This paper outlines the characteristics of data and operations in some advanced database applications, discusses their concurrency control requirements, and surveys the mechanisms proposed to address these requirements.

The Apache HTTP Server Project

Most reports of Internet collaboration refer to small scale operations among a few authors or designers. However, several projects have shown that the Internet can also be the locus for large scale collaboration. In these projects, contributors from around the world combine their individual forces and develop a product that rivals those of multibillion dollar corporations. The Apache HTTP Server Project is a case in point. This collaborative software development effort has created a robust, feature-rich HTTP server software package that currently dominates the public Internet market (46 percent compared with 16 percent for Microsoft and 12 percent for Netscape, according to a June 1997 survey published by Netcraft). The software and its source code are free, but Apaches popularity is more often attributed to performance than price. The project is managed by the Apache Group, a geographically distributed group of volunteers who use the Internet and Web to communicate, develop, and distribute the server and its related documentation. In addition, hundreds of users have contributed ideas, code, and documentation to the project.

Intelligent assistance for software development and maintenance

An environment is described, called Professor Marvel, that provides early error checking and answers questions about the program under development. The environment has a certain understanding of the systems being developed and how to use tools to produce software. It aids individual programmers and helps coordinate programming teams. The key components of Marvel are a database that stores data represented as objects, as in object-oriented languages, and a model of the development process that imposes a structure on programming activities. Marvels support of insight and of opportunistic processing is discussed at length, as is the handling of side effects. A sample session is described.<<ETX>>

Split-Transactions for Open-Ended Activities

Open-ended activities such as CAD/CAM, VLSI layout and software development require consistent concurrent access and fault tolerance associated with database transactions, but their uncertain duration, uncertain developments during execution and long interactions with other concurrent activities break traditional transaction atomicity boundaries. We propose splittransaction as a new database operation that solves the above problems by permitting transactions to commit data that will not change. Thus an open-ended activity can release the committed data and serialize interactions with other concurrent activities through the committed data.

A control theory foundation for self-managing computing systems

The high cost of operating large computing installations has motivated a broad interest in reducing the need for human intervention by making systems self-managing. This paper explores the extent to which control theory can provide an architectural and analytic foundation for building self-managing systems. Control theory provides a rich set of methodologies for building automated self-diagnosis and self-repairing systems with properties such as stability, short settling times, and accurate regulation. However, there are challenges in applying control theory to computing systems, such as developing effective resource models, handling sensor delays, and addressing lead times in effector actions. We propose a deployable testbed for autonomic computing (DTAC) that we believe will reduce the barriers to addressing research problems in applying control theory to computing systems. The initial DTAC architecture is described along with several problems that it can be used to investigate.

A paradigm for decentralized process modeling and its realization in the Oz environment

We present a model for decentralized Process Centered Environments (PCEs), which support concerted efforts among geographically-dispersed teams - each local team with its own autonomous process - and emphasize flexibility in the tradeoff between collaboration vs. autonomy. We consider both decentralized process modeling and decentralized process enaction. We describe a realization in the OZ decentralized PCE, which employs a rule-based formalism, and also investigate the application to PCEs based on Petri-nets.<<ETX>>

Automating Content Extraction of HTML Documents

Abstract Web pages often contain clutter (such as unnecessary images and extraneous links) around the body of an article that distracts a user from actual content. Extraction of “useful and relevant” content from web pages has many applications, including cell phone and PDA browsing, speech rendering for the visually impaired, and text summarization. Most approaches to making content more readable involve changing font size or removing HTML and data components such as images, which takes away from a webpage’s inherent look and feel. Unlike “Content Reformatting,” which aims to reproduce the entire webpage in a more convenient form, our solution directly addresses “Content Extraction.” We have developed a framework that employs an easily extensible set of techniques. It incorporates advantages of previous work on content extraction. Our key insight is to work with DOM trees, a W3C specified interface that allows programs to dynamically access document structure, rather than with raw HTML markup. We have implemented our approach in a publicly available Web proxy to extract content from HTML web pages. This proxy can be used both centrally, administered for groups of users, as well as by individuals for personal browsers. We have also, after receiving feedback from users about the proxy, created a revised version with improved performance and accessibility in mind.

Melding Software Systems from Reusable Building Blocks

This declarative language takes the best features from the three most popular reusability approaches, but overcomes their flaws. It supports language independence, component composition, and tailoring.

SWAP: leveraging the Web to manage workflow

Many organizations are beginning to discover what workflow vendors already know-namely, that the real value of the Web lies not just in its documents and resources, but also in the activities surrounding them. Collaborative work involves not only handoff and routing of data between humans, but the coordination of activities among them and with automated agents as well. Workflow engines typically ensure that the information ends up on the right desktop along with the tools to accomplish a slated task. It is difficult to synchronize work and activity tracking within a technically diverse organization. Tools and formats typically differ among workgroups, as do skill levels and understanding among individual participants in a process. Browser-based user interfaces offer a mechanism to easily access distributed information and hand off documents and data over the Web, but at the expense of being able to effectively manage and track work activities. Web protocols provide no inherent support for automated change notification, handoff of control, or initiation of human- and computer-executed activities. In essence, there is no standard way for service requests to trigger a workflow process and monitor it across platforms and between organizations.