Allen Moulton

Context mediation on Wall Street

The paper reports on a practical implementation of a context mediator for the fixed income securities industry. The authors describe industry circumstances and the data and calculation services (DCS) mediator developed and deployed in the early 1990s. The mediator was designed as an interpretive engine controlled by a static declarative knowledge structure and client preference data. In addition to heterogeneous, autonomous data sources, the mediator integrated autonomously developed local and remote procedural components. Client access to both data and computational resources were provided through an active conceptual model. Structural and semantic context conversions were used to integrate disparate components and to support varying client needs. Lessons learned from the implementation and usage of this mediator provide insight into the requirements for a successful context mediator.

Semantic Information Integration in the Large: Adaptability, Extensibility, and Scalability of the Context Mediation Approach

There is pressing need for effectively integrating information from an ever increasing number of available sources both on the web and in other existing systems. A key difficulty of achieving this goal comes from the pervasive heterogeneities in all levels of information systems. Existing and emerging technologies, such as the Web, ODBC, XML, and Web Services, provide essential capabilities in resolving heterogeneities in the hardware and software platforms, but they do not address the semantic heterogeneity of the data itself. A robust solution to this problem needs to be adaptable, extensible, and scalable. In this paper, we identify the deficiencies of traditional approaches that address this problem using hand-coded programs or require complete data standardization. The COntext INterchange (COIN) approach overcomes these deficiencies by declaratively representing data semantics and using a mediator to create the necessary conversion programs using a small number of conversion rules. The capabilities of COIN is demonstrated using an intelligence information integration example consisting of 150 data sources, where COIN can automatically generate the over 22,000 conversion programs needed to enable semantic integration using only six pa

Framework for the Analysis of the Adaptability, Extensibility, and Scalability of Semantic Information Integration and the Context Mediation Approach

Technological advances such as Service Oriented Architecture (SOA) have increased the feasibility and importance of effectively integrating information from an ever widening number of systems within and across enterprises. A key difficulty of achieving this goal comes from the pervasive heterogeneity in all levels of information systems. A robust solution to this problem needs to be adaptable, extensible, and scalable. In this paper, we identify the deficiencies of traditional semantic integration approaches. The COntext INterchange (COIN) approach overcomes these deficiencies by declaratively representing data semantics and using a mediator to create the necessary conversion programs from a small number of conversion rules. The capabilities of COIN is demonstrated using an example with 150 data sources, where COIN can automatically generate the over 22,000 conversion programs needed to enable semantic interoperability using only six parametizable conversion rules. This paper presents a framework for evaluating adaptability, extensibility, and scalability of semantic integration approaches. The application of the framework is demonstrated with a systematic evaluation of COIN and other commonly practiced approaches.

SCRIPT, An On-Line Manuscript Processing System

The SCRIPT commands of the IB CP67/ CMS system provide interactive creation and editing of manuscript text, and can format and output hard copies. The primary goal of SCRIPT was a convenient method within an on-line system to permit programmers to prepare and maintain system documents. The SCRIPT commands have, however, also been used extensively to prepare technical reports and papers of all kinds. The EDIT module creates and operates upon a file in secondary storage. Lines of text from the typewriter terminal are put into canonical form and added to or inserted in the file. Editing instructions can reference a line either by context or relative line number, and can change strings within the line to other strings, as well as retype, delete, or insert whole lines. The PRINT module formats the manuscript file and outputs it to either the typewriter or line printer. Lines are left and right justified by adding additional embedded blanks where necessary. A logical topology data structure correctly interprets overprinting characters. Format control lines may be inserted in the text to specify such additional features as heading lines, line length, page length, page numbering, centering, indentation, and double spacing. The design of a follow-on system with major changes in each of these areas is discussed (see Fig. 5 of the text).

Effects of Funding Fluctuations on Software Development: A System Dynamics Analysis

Abstract What happens when software project funding is temporarily cut off and then restored at a later date? Although project funding gaps clearly result in software delivery delays, it is difficult to understand the causes and estimate the relative magnitude of the impact. This article uses System Dynamics modeling to examine how gaps in funding affect software development productivity and product delivery delay. Results provide software engineering managers with an improved sense of the negative effect of budget fluctuations. Two key insights for practicing engineering managers include a Ramp Up Tax that slows development and a Gap Tax due to the loss of project-related skill and familiarity when developers are transferred off a project and then return. Model experiments presented allow managers to compare the impact of temporarily stopping a project versus stretching out a project by temporarily reducing the funding level. Both the model and the patterns of results can provide project managers with a stronger basis for explaining the negative effects of funding gaps to senior leadership and funding managers.

An Active Conceptual Model for Fixed Income Securities Analysis for Multiple Financial Institutions

The practical implementation and use of a mediator for fixed income securities analysis demonstrated the potential for extending the application of conceptual modeling from the system design stage to providing query access to both data and computational resources. The mediator product was designed as a general interpretive engine specialized and controlled by the declarative knowledge from the conceptual model. The fixed income conceptual model included securities ranging in complexity from Treasury bills to collateralized mortgage obligations, as well as standard and proprietary analytic methodologies and calculations. All information, whether computed or retrieved from databases, was offered to clients in the form of attributes of conceptual entities. Client preference entities and attributes were used to control selection among conceptually interchangeable source data and procedural components. Experience from this implementation provides insight into the requirements for successful application of a conceptual model in mediating among heterogeneous, autonomous users and information resources.

A temporal and spatial locality theory for characterizing very large data bases

Theoretical results in formally defining and measuring database locality are presented. Database locality has proved less tractable than program locality, which has a long history of theoretical investigation and application in virtual memory systems and processor catches. The stages at which database locality can be observed and the differences between database and program locality are identified. A technique for adapting the program locality model to both temporal and spatial dimensions at all stages of database processing is developed. A case study of a large commercial database is used to illustrate the application of the database locality model and the interpretation of results.<<ETX>>

Context Mediation Demonstration of Counter-Terrorism Intelligence Integration

In this report, we demonstrate the applicability and value of the context mediation approach in facilitating the effective and correct use of counter-terrorism intelligence information coming from diverse heterogeneous sources.