Security of service usage in a heterogeneous independently-operated interoperable cloud computing environments (ICE), is a multi-faceted problem, from trust in service performance in conformance with the service specification, to trust in and security of the interaction between the service requestor and service. These issues are compounded in an ICE as there may not be a single source of trust or guarantor or centralized enforcer of security and other control mechanisms. This paper proposes a solution to the problem of trust and security of the interaction between the service requestor and service provider in an ICE, and presents its performance under various threat scenarios.

Cloud based services, by their nature, are distributed and traditional operation and management processes that often exert centralized control are not suited for cloud services operation and management. This paper introduces a Policy-based Event-driven Service-oriented Architecture (PESA) that enables the manageability of these loosely coupled services distributed across multiple public or private clouds or a hybrid cloud. PESA allows the implementation of policy driven management of service availability, performance, security and risk management. Using the concept of logical and virtual partitioning of the business service fabric into sub-fabrics - islands of services that may span company, geographical, and technological boundaries, public and private clouds, and corporate data centers, we describe a conceptual management architecture for policy enforcement. An example describes service availability and performance assurance in a business process implementation using a set of loosely coupled service components in a virtual cloud.

The authors consider B/sub c/-trees in a centralized system with large main memory, and show that in some cases the join operation using B/sub c/-trees out performs other join techniques. The results can be used for estimating the cost of join using B/sub c/-trees and then making a decision regarding the most efficient join technique to be used.>

This paper proposes a dictionary machine which can handle redundant instructions on a modified semi X-tree structure in one pass. The proposed machine which is based on Leiseron's3 design operates with a pipeline interval of two steps. The cell complexity of the design is comparable to that of Leiserson's. Unlike other designs4,5,6 where cell complexity, pipeline interval and structure are compromised to get optimal response time, in this design, response time is compromised to get better pipeline interval, cell complexity and structure. The reason for taking this approach is presented in the paper.

The aim of this article is to present a simple encoding technique that can be profitably utilized in program storage. Among the benefits of an editor that utilizes such an encoding is the reduced costs in lexical analysis stages of software tools, such as language translators and pretty printers. Based on the analysis of a set of PASCAL programs, the possible benefits in storage and compilation are analyzed. © 1987 John Wiley & Sons, Inc.

Individualized data structures and operations have been devised for the various application areas of textual data. Consequently, their ability to integrate with other applications by sharing their data objects has been lost. In this article we present a data model based on the text data model, universal relation model and nonfirst normal form relations, and discuss the applicability of this data model to text processing and document retrieval systems. © 1986 John Wiley & Sons, Inc.

Abstract This study Investigates various techniques for the automatic coding of English Language strings. The strings are titles drawn from bibliographic files, but the techniques do not require any prior knowledge of the source. Variations of the techniques have also been tested and it has been shown that string abbreviation or coding based on the maximum entropy principle gives the best results. Some of the reasons for the nonuniqueness of the generated codes are presented.