Building a knowledge base: an example

The main goal of this paper is to illustrate applications of some recent developments in the theory of logic programming to knowledge representation and reasoning in common sense domains. We are especially interested in better understanding the process of development of such representations together with their specifications. We build on the previous work of Gelfond and Przymusinska in which the authors suggest that, at least in some cases, a formal specification of the domain can be obtained from specifications of its parts by applying certain operators on specifications called specification constructors and that a better understanding of these operators can substantially facilitate the programming process by providing the programmer with a useful heuristic guidance. We discuss some of these specification constructors and their realization theorems which allow us to transform specifications built by applying these constructors to declarative logic programs. Proofs of two such theorems, previously announced in a paper by Gelfond and Gabaldon, appear here for the first time. The method of specifying knowledge representation problems via specification constructors and of using these specifications for the development of their logic programming representations is illustrated by design of a simple, but fairly powerful program representing simple hierarchical domains. This revised version was published online in June 2006 with corrections to the Cover Date.     

MICO: an open source CORBA implementation

The Common Object Request Broker Architecture is a specification for creating, distributing, and managing distributed program objects across a network. Both the International Organization for Standardization and X/Open have sanctioned CORBA as the standard middleware architecture for distributed objects. CORBA was specifically designed to support heterogeneous environments, different vendors' products, and several popular programming languages. MICO is an OSS implementation of CORBA. Inspired by the GNU project, the name "MICO" stands for "MICO Is CORBA". MICO has evolved into a mature open source project, with close to a half million lines of source code contributed by more than 150 programmers. The author discusses MICO's internal architecture and then offers a few guidelines to choose the right CORBA implementation for your purposes.     

Approximate verification in an open source world

This article details advances in a lightweight technology we have evolved to handle post hoc verification in the very large, uncontrolled and rapidly evolving code-bases exemplified by C language open source projects such as the Linux kernel. Successful operation in this context means timeliness, and we are currently treating millions of lines of unrestricted mixed C and assembler source code in a few hours on very modest platforms. The technology is soundly based, in that it delivers false alarms (in a ratio of about 8 to 1 in practice), rather than misses true alarms. Speed of operation is traded off against accuracy via configuration of a program logic tailored to each analysis. The program logic specification language and the theory behind it will be described here.     

Implementing an open link service for the World Wide Web

Links are the key element for changing a text into a hypertext, and yet the WWW provides limited linking facilities. Modeled on Open Hypermedia research the Distributed Link Service provides an independent system of link services for the World Wide Web and allows authors to create configurable navigation pathways for collections of WWW resources. This is achieved by adding links to documents as they are delivered from a WWW server, and by allowing the users to choose the sets of links that they will see according to their interests. This paper describes the development of the link service, the facilities that it adds for users of the WWW and its specific use in an Electronic Libraries project.     

OpenRatSLAM: an open source brain-based SLAM system

RatSLAM is a navigation system based on the neural processes underlying navigation in the rodent brain, capable of operating with low resolution monocular image data. Seminal experiments using RatSLAM include mapping an entire suburb with a web camera and a long term robot delivery trial. This paper describes OpenRatSLAM, an open-source version of RatSLAM with bindings to the Robot Operating System framework to leverage advantages such as robot and sensor abstraction, networking, data playback, and visualization. OpenRatSLAM comprises connected ROS nodes to represent RatSLAM’s pose cells, experience map, and local view cells, as well as a fourth node that provides visual odometry estimates. The nodes are described with reference to the RatSLAM model and salient details of the ROS implementation such as topics, messages, parameters, class diagrams, sequence diagrams, and parameter tuning strategies. The performance of the system is demonstrated on three publicly available open-source datasets.     

Toward an architectural knowledge base for wireless service engineering

Wireless services are software-based services that exploit distribution infrastructure embedded in our everyday life as various communication and computing technologies. Service architecture defines concepts and principles to develop and maintain services to obtain the quality issues with minimum cost and faster time-to-market. In order to boost the development of wireless services, more effective means of using existing architectural know-how and artifacts are required. Our contribution is the architectural knowledge base that introduces three cornerstones: the service taxonomy, reference service architecture, and basic services that alt together provide an efficient means of creating added value with wireless services. The service taxonomy assists in identifying the required functional and quality properties of services and the constraints of the underlying technology platforms. The reference architecture realizes the required properties, based on a selected set of architectural styles and patterns, and provides a skeleton upon which a new end-user service can be developed faster and more easily by using partially ready-made solutions, and furthermore, to keep the architectural knowledge base evolving at the same time. The architectural knowledge base has been validated in several research projects with industrial companies.     

Image selection and annotation for an environmental knowledge base

Images play an important role in the representation and acquisition of specialized knowledge. Not surprisingly, terminological knowledge bases (TKBs) often include images as a way to enhance the information in concept entries. However, the selection of these images should not be random, but rather based on specific guidelines that take into account the type and nature of the concept being described. This paper presents a proposal on how to combine the features of images with the conceptual propositions in EcoLexicon, a multilingual TKB on the environment. This proposal is based on the following: (1) the combinatory possibilities of concept types; (2) image types, such as photographs, drawings and flow charts; (3) morphological features or visual knowledge patterns (VKPs), such as labels, colours, arrows, and their effect on the functional nature of each image type. Currently, images are stored in association with concept entries according to the semantic content of their definitions, but they are not described or annotated according to the parameters that guided their selection, which would undoubtedly contribute to the systematization and automatization of the process. First, the images included in EcoLexicon were analyzed in terms of their adequateness, the semantic relations expressed, the concept types and their VKPs. Then, with these data, guidelines for image selection and annotation were created. The final aim is twofold: (1) to systematize the selection of images and (2) to start annotating old and new images so that the system can automatically allocate them in different concept entries based on shared conceptual propositions.     

Developing an information systems infrastructure with open source software

Up to now, most open source software deployments have been in invisible infrastructure applications running on back-office servers (GNU/Linux, Apache, and so on). Beaumont Hospital in Ireland recently started developing its overall information systems infrastructure by deploying more visible desktop and front-office open source applications in addition to GNU/Linux and Apache. In a two-phase open source implementation, Beaumont will save over /spl euro/ 20 million over five years.     

Development of an intelligent knowledge base for heat stress evaluation

An intelligent knowledge base system for heat stress evaluation is described. The evaluation of heat stress is a particularly difficult problem, utilizing a variety of sometimes contradictory heat stress indices, and thus is naturally suited for computer aided design. The present system uses an expert system approach and can be used either as a stand along design tool or as one of the lower level models for larger ergonomic expert systems such as ALFIE. Simulations of a variety of environmental conditions were performed. A large diversity in predictive capabilities was found, depending on the assumptions used for each component index. For maximum efficiency with novice users, further explanations and on-line assistance need to be implemented within the system.     

IGSTK: an open source software toolkit for image-guided surgery

Image-guided surgery applies leading-edge technology and clinical practices to provide better quality of life to patients who can benefit from minimally invasive procedures. Reliable software is a critical component of image-guided surgical applications, yet costly expertise and technology infrastructure barriers hamper current research and commercialization efforts in this area. IGSTK applies the open source development and delivery model to this problem. Agile and component-based software engineering principles reduce the costs and risks associated with adopting this new technology, resulting in a safe, inexpensive, robust, shareable, and reusable software infrastructure.     

Understanding knowledge sharing activities in free/open source software projects: An empirical study

Free/Open Source Software (F/OSS) projects are people-oriented and knowledge intensive software development environments. Many researchers focused on mailing lists to study coding activities of software developers. How expert software developers interact with each other and with non-developers in the use of community products have received little attention. This paper discusses the altruistic sharing of knowledge between knowledge providers and knowledge seekers in the Developer and User mailing lists of the Debian project. We analyze the posting and replying activities of the participants by counting the number of email messages they posted to the lists and the number of replies they made to questions others posted. We found out that participants interact and share their knowledge a lot, their positing activity is fairly highly correlated with their replying activity, the characteristics of posting and replying activities are different for different kinds of lists, and the knowledge sharing activity of self-organizing Free/Open Source communities could best be explained in terms of what we called “Fractal Cubic Distribution” rather than the power-law distribution mostly reported in the literature. The paper also proposes what could be researched in knowledge sharing activities in F/OSS projects mailing list and for what purpose. The research findings add to our understanding of knowledge sharing activities in F/OSS projects.     

Crack open the source

Open source is now an established part of the mainstream computing.Companies like Sun, Novell and IBM increasingly supporting opensource, it's clearly about more than just fun free stuff. Butare open source tools suitable for use in project managementactivities? Anthony Harrison from Thales investigates.     

Constructing and consulting the knowledge base of an expert systems shell

Abstract: This paper presents an expert system shell whose inference mechanism uses backward chaining. In particular the modules devoted to constructing and consulting the knowledge base are illustrated. The programming environment is based on the Arity-Prolog language, a popular Prolog dialect running on IBM PCs and compatibles.     

Integration of an energy balance snowmelt model into an open source modeling framework

This paper presents a data model for organizing the inputs and outputs of an energy balance snowmelt model (the Utah Energy Balance Model, UEB) that provides a foundation for its integration into the EPA BASINS modeling framework and enables its coupling with other hydrologic models in this system. Having UEB as a BASINS component has facilitated its coupling with the Geospatial Streamflow Forecast Model (GeoSFM) to compute the melting of glaciers and subsequent streamflow in the Himalayas. The data model uses a combination of structured text and network Common Data Form (netCDF) files to represent parameters, geographical, time series, and gridded space-time data. We describe the design and structure of this data model, integration methodology of UEB and GeoSFM and illustrate the effectiveness of the resulting coupled models for the computation of surface water input and streamflow for a glaciated watershed in Nepal Himalayas.     

Building knowledge base management systems

Advanced applications in fields such as CAD, software engineering, real-time process control, corporate repositories and digital libraries require the construction, efficient access and management of large, shared knowledge bases. Such knowledge bases cannot be built using existing tools such as expert system shells, because these do not scale up, nor can they be built in terms of existing database technology, because such technology does not support the rich representational structure and inference mechanisms required for knowledge-based systems. This paper proposes a generic architecture for a knowledge base management system intended for such applications. The architecture assumes an object-oriented knowledge representation language with an assertional sublanguage used to express constraints and rules. It also provides for general-purpose deductive inference and special-purpose temporal reasoning. Results reported in the paper address several knowledge base management issues. For storage management, a new method is proposed for generating a logical schema for a given knowledge base. Query processing algorithms are offered for semantic and physical query optimization, along with an enhanced cost model for query cost estimation. On concurrency control, the paper describes a novel concurrency control policy which takes advantage of knowledge base structure and is shown to outperform two-phase locking for highly structured knowledge bases and update-intensive transactions. Finally, algorithms for compilation and efficient processing of constraints and rules during knowledge base operations are described. The paper describes original results, including novel data structures and algorithms, as well as preliminary performance evaluation data. Based on these results, we conclude that knowledge base management systems which can accommodate large knowledge bases are feasible. Edited by Gunter Schlageter and H.-J. Schek. Received May 19, 1994 / Revised May 26, 1995 / Accepted September 18, 1995     

E-DEVICE: an extensible active knowledge base system with multiplerule type support

This paper describes E-DEVICE, an extensible active knowledge base system (KBS) that supports the processing of event-driven, production, and deductive rules into the same active OODB system. E-DEVICE provides the infrastructure for the smooth integration of various declarative rule types, such as production and deductive rules, into an active OODB system that supports low-level event-driven rules only by: (1) mapping each declarative rule into one event-driven rule, offering centralized rule selection control for correct run-time behavior and conflict resolution, and (2) using complex events to map the conditions of declarative rules and monitor the database to incrementally match those conditions. E-DEVICE provides the infrastructure for easily extending the system by adding: (1) new rule types as subtypes of existing ones, and (2) transparent optimizations to the rule matching network. The resulting system is a flexible, yet efficient, KBS that gives the user the ability to express knowledge in a variety of high-level forms for advanced problem solving in data intensive applications