Insurance Portfolio Analysis (IPA) is the process of comparing multiple, potentially overlapping insurance portfolios with an eye to detecting and characterizing redundancies and gaps in coverage. Unfortunately, insurees usually do not have the time or patience to compare policies from multiple insurance providers, and they often do not have the legal background needed to understand the complex legal wording of the contracts associated with those policies. Past work has shown that, by encoding policies as logic programs, it is possible to automatically determine compliance of specific claims with a policy’s terms and conditions. In this paper, we show that it is also possible to automatically analyze multiple-policy portfolios for gaps and redundancies by assessing coverage over multiple hypothetical claims. We formalize the process of IPA and show how to use well-studied techniques for logic program containment testing to automate the process.

For increasingly sophisticated use cases end users often need to extract, combine, and aggregate information from various (often dynamically generated) web pages from multiple websites. Current search engines do not focus on combining information from various web pages in order to answer the overall information need of the user. Semantic Web and Linked Data usually take a static view on the data and rely on providers' cooperation. In this paper, we present a novel approach that enables end users to easily extract data from web pages while they browse, store it locally in their browser as well as structure, integrate and search such data. We propose Datalog rules for integrating and searching the extracted data. We show how cleaning steps and integration rules can be reused to accelerate the cleaning and integration of extracted data. The proposed approach is implemented as a browser plugin. We present its implementation details and report on our evaluation of the plugin concerning user experience and browsing time saving.

Run-length encoding is a popular compression scheme which is used extensively to compress the attribute values in column stores. Out of order insertion of tuples potentially degrades the compression achieved using run-length encoding and consequently, the performance of reads. The in-place insertions, deletions and updates of tuples into a column store relation with n tuples take O(n) time. The linear cost is typically avoided by amortizing the cost of updates in batches. However, the relation is decompressed and subsequently re-compressed after applying a batch of updates. This leads to added time time complexity. We propose a novel indexing scheme called count indexes that supports O(log n) in-place insertions, deletions, updates and look ups on a run-length encoded sequence with n runs. We also show that count indexes efficiently update a batch of tuples requiring almost a constant time per updated tuple. Additionally, we show that count indexes are optimal. We extend count indexes to support O(log n) updates on bitmapped sequences with n values and adapt them to block-based stores.

We consider the problem of finding equivalent minimal-size reformulations of SQL queries in presence of embedded dependencies [1]. Our focus is on select-project-join (SPJ) queries with equality comparisons, also known as safe conjunctive (CQ) queries, possibly with grouping and aggregation. For SPJ queries, the semantics of the SQL standard treats query answers as multisets (bags), whereas the stored relations are treated either as sets, which is called bag-set semantics, or as bags, which is called bag semantics. (Under set semantics, both query answers and stored relations are treated as sets.)

Computationally represented laws should accurately model their real-world counterparts in rules-based legal compliance systems. Legal theoretical considerations, however, often complicate the task of faithful representation. One approach to this problem has been to create sophisticated models capable of representing rules of arbitrary legal complexity. An alternative approach, which we advocate in this paper, is to focus on a subset of individual legal rules which are more amenable to simplified computational representation from a legal theoretical perspective. We propose a measure of such a tendency that we term the representational complexity of a legal rule. Our approach involves a systematic examination of particular legal rules along all of the relevant dimensions of legal theoretical complexity identified by the legal scholarship. In this way, we suggest that is possible to identify discrete legal rules which are likely to be, from a legal theoretical standpoint, amenable to simpler computational representation.

Computational law is an approach to automated legal reasoning focusing on semantically rich laws, regulations, contract terms, and business rules in the context of electronically-mediated actions. Current computational tools for electronic commerce fall short of the demands of business, organizations, and individuals conducting complex transactions over the web. However, the growth of semantic data in the world of electronic commerce and online transactions, coupled with grounded rulesets that explicitly reference that data, provides a setting where applying automated reasoning to law can yield fruitful results, reducing inefficiencies, enabling transactions and empowering individuals with knowledge of how laws affect their behavior.

We consider the problem of answering datalog queries using materialized views.The abiity to answer queries using views is crucial in the context of information integration.Previous work on answering queries using views restricted queries to being conjunctive.We extend this work to general recursive queries:Given a datalog program P and a set of views, is it possible to find a datalog program that is equivalent to P and only uses views as EDB predicates?In this paper, we show that the problem of whether a datalog program can be rewritten into an equivalent program that only uses views is undecidable.On the other hand, we prove that a datalog program P can be effectively rewritten into a program that only uses views, that is contained in P, and that contains all programs that only use views and are contained in P. As a consequence, if there exists a program equivalent to 'P that only uses views, then our construction is guaranteed to yield a program equivalent to P.

Infomaster is an information integration system that provides integrated access to multiple distributed heterogeneous information sources on the Internet, thus giving the illusion of a centralized, homogeneous information system. We say that Infomaster creates a virtual data warehouse. The core of Infomaster is a facilitator that dynamically determines an efficient way to answer the user's query using as few sources as necessary and harmonizes the heterogeneities among these sources. Infomaster handles both structural and content translation to resolve differences between multiple data sources and the multiple applications for the collected data. Infomaster connects to a variety of databases using wrappers, such as for Z39.50, SQL databases through ODBC, EDI transactions, and other World Wide Web (WWW) sources. There are several WWW user interfaces to Infomaster, including forms based and textual. Infomaster also includes a programmatic interface and it can download results in structured form onto a client computer. Infomaster has been in production use for integrating rental housing advertisements from several newspapers (since fall 1995), and for meeting room scheduling (since winter 1996). Infomaster is also being used to integrate heterogeneous electronic product catalogs.

The support for automatic interoperation of software components can reduce cost and provide greater functionality. This paper describes a novel approach to software interoperation based on specification sharing. Software components, called agents, provide machine processable descriptions of their capabilities and needs. Agents can be realized in different programming languages, and they can run in different processes on different machines. In addition, agents can be dynamic — at run time agents can join the system or leave. The system uses the declarative agent specifications to automatically coordinate their interoperation. The architecture supports anonymous interoperation of agents, where each agent has the illusion that the capabilities of all the other agents are provided directly by the system. The distinctive feature of this approach is the expressiveness of the declarative specification language, which enables sophisticated agent interoperation, e.g. decomposing complex requests into a collection of simpler requests, and translating between the interface of a requesting agent and the interface of an agent that can service the request. The agent-based interoperation scheme relies on a shared vocabulary, and it is our thesis that more effective software interoperation is made possible by agreeing to a shared declarative vocabulary, than by agreeing to procedural interface specifications that do not address the semantics of the software component (e.g. object interface specifications in an object-oriented programming environment).

For those of us in the Stanford Logic Group, the Dart project marks the beginning of a long-term commitment to research on the use of computers in the service of engineering. Oddly enough, the project began not in engineering, but in medicine; and it was originally concerned with explanation, not diagnosis. When I arrived at Stanford in 1979, I assembled a small research group with financial support from a research contract belonging to Bruce Buchanan and Ed Feigenbaum. I asked Bruce how we might earn our keep, and he suggested that we look into ways of improving Mycin's explanation capability. Mycin was already world-renowned for its ability to explain its conclusions by citing the data and rules used to make those conclusions. The problem was that it was unable to explain why its rules were correct. We knew that physicians could supply rationale for many of Mycin's rules by reference to underlying physiological principles. So, our idea was to capture this physiological knowledge and produce a program that could use it to verify Mycin's rules. A trace of the verification could then be used to explain the rules.

A formal framework is presented that models communication and promises in multi-agent interactions. This framework generalizes previous work on co-operation without communication (Genesereth et al. 1984a, Genesereth et al. 1986), and shows the ability of communication to resolve conflicts among agents having disparate goals. Using a one-phase deal-making mechanism, agents are able to coordinate and cooperate more easily than in the communication-free model. In addition, there are certain types of interactions where communication makes possible mutually beneficial activity that is otherwise impossible to coordinate.

Designworld is an automated engineering system for digital circuits built from standard parts (TTL chips and prototyping boards). The distinguishing feature of the system is that it provides integrated support for various phases in the life cycle of a product-from design, through manufacture, to maintenance. The design for a product is entered via a multimedia design workstation; the product is built automatically by a dedicated robotic cell; and, if necessary, the product, once built, can be returned to the system for automatic diagnosis and repair.>