Stepwise Redesign of Distributed Relational Databases

this paper, we address the problem of stepwis

A logical framework for security enforcement in CapBasED-AMS

The CapBasED-AMS (Capability-based and Event-driven Activity Management System) deals with the management and execution of activities. A Problem Solving Agent (PSA) is a human, or a hardware system, or a software system having an ability to execute activities. An activity consists of multiple inter-dependent tasks that need to be coordinated, scheduled and executed by a set of PSAs. Since security is essential and integral part of activities, the activity management system has to manage and execute the activities in a secure way. In the CapBasED-AMS, threats, such as, unauthorized access or modification are identified as events. In this paper, we develop a logical framework for security enforcement in CapBasED-AMS by taking into consideration the system infrastructure, secure match-making under security constraints, security policies and secure PSA, the task coordination model for security enforcement during activity execution

Security enforcement in activity management systems

Security enforcement is an issue of paramount importance for any system that facilitates computer supported cooperative work. An activity management system is a software that facilitates specification and decomposition, and execution of activities. An activity is a set of coordinated tasks (atomic activities). The focus of this paper is on supporting security in activity management systems. In particular, we present an architecture, and describe the mechanisms that need to be incorporated for enforcing security for activity specification and decomposition, and during activity execution. This paper provides a task-centered approach towards security enforcement, wherein, the security constraints are checked and the task is allowed to be executed only if none of the security constraints are violated. This is handled by the event-condition-action rule paradigm from active database systems

A framework for class partitioning in object-oriented databases

In order to support homogeneous distributed object oriented database systems we need to have a clear understanding of what is meant by partitioning a class and what are the different ways of doing so. In this paper, we concentrate on studying the different types of class partitioning schemes that can arise in object oriented databases. To come up with a general-purpose design methodology, we present a framework of devising partitioning schemes based on different types of methods and their classification. We also address the issue of "fragmentation transparency" by considering appropriate method transformation techniques. By laying down the foundation by articulating the concepts, representation, and implementation approaches for partitioning object databases, we facilitate further work on partitioning algorithms, query decomposition, optimization and transaction management for distributed OODBMS

Optimal pricing strategies for Internet-based software dissemination

In the recent past, there have been several initiatives by major software companies, such as Microsoft, to lead the industry towards electronic software distribution, in this paper, we use a monopoly pricing model to examine the optimal pricing strategies for `selling' and `pay-per-use' licensing of packaged software over the Internet. Traditionally, software distribution included outright sale as well as short/long term renting. With the Internet fast becoming a prevalent mode for disseminating software, a customer can download and use software on a need-by-need basis. For the software vendor, offering the pay-per-use option to the consumer provides for a steady source of revenue and obviates the need for physical distribution, purchasing and inventory management mishaps. We examine the following issues in this paper: (i) what are the extra benefits to the software vendor for providing the pay-per-use option?; and (ii) does the market size change? The contribution of this paper is to show that pay-per-use is a viable alternative for a large number of customers, and that judicious pricing for pay-per-use is profitable for the software vendor

A framework for speeding up workflow instances by exploiting alternate paths

Workflow systems have been deployed in organizations to facilitate efficient, consistent, and accurate handling of business processes. But as in real life, there are many, different ways to do work, with varying cost and completion times. In this paper we augment workflow systems by providing modelling support for alternate paths with models for calculating the completion times and the cost for executing a workflow. Further. we design scheduling algorithms to facilitate execution of workflow instances to meet user requirements on completion times and cost of execution

Least privilege security in CapBasED-AMS

Workflow systems are becoming very popular and are being used to support many of the day to day activities in large organizations. One of the major problems with workflow systems is that they often use heterogeneous and distributed hardware and software systems to execute a given activity. This gives rise to decentralized security policies and mechanisms, which, in order to enable activity execution, give too many privileges (for accessing resources like documents) to the agents (humans or systems) for executing the work. We develop the concept of least privilege, wherein the set of agents are given just enough privileges to complete the given activities. We develop our concepts in the context of CapBasED-AMS (Capability-based and Event-driven Activity Management System). The CapBasED-AMS deals with the management and execution of activities. An activity consists of multiple inter-dependent tasks (atomic activities, each executed by a single agent) that need to be coordinated, scheduled and executed by a set of agents. We formalize the concept of least privilege security and present algorithms to statically assign least privilege assignment to the agents. Further, we develop the concept of dynamic least privilege enforcement, wherein an agent is given its privileges only during the duration of the task for which those privileges were assigned. We also develop the concept of dynamic evolution of least privileges by taking into consideration the changes in the way resources are accessed by the agents in executing their tasks. Finally, we address the trade-off between resilience to agent failure and least privilege

Speeding up electronic commerce activities using CapBasED-AMS

CapBasED-AMS is a capability based and event driven activity management system that supports specification and execution of activities using cooperative information systems paradigm. In CapBasED, an activity consists of interdependent tasks (atomic activities) that are executed by an agent. When there are many activity instances executing at the same time many tasks are queued up at agents for execution. In this paper, lye propose a multi-agent system model, introduce a measurement of speed-up/slow-down, and develop different scheduling policies that allows for faster executions based on user's requests. Our scheduling framework is developed under the assumption that there are no additional resources for speeding-tip the activities and it is based on re-scheduling activities in agent's queues