The emergence of cloud computing infrastructure and Semantic Web technologies has created unprecedented opportunities for composing large-scale business processes and workflow-based applications that span multiple organizational domains. A key challenge related to composition of such multi-organizational business processes and workflows is posed by the security and access control policies of the underlying organizational domains. In this paper, we propose a framework for verifying secure composability of distributed workflows in an autonomous multi-domain environment. The objective of workflow composability verification is to ensure that all the users or processes executing the designated workflow tasks conform to the time-dependent security policy specifications of all collaborating domains. A key aspect of such verification is to determine the time-dependent schedulability of distributed workflows, assumed to be invoked on a recurrent basis. We use a two-step approach for verifying secure workflow composability. In the first step, a distributed workflow is decomposed into domain-specific projected workflows and is verified for conformance with the respective domain's security and access control policy. In the second step, the cross-domain dependencies amongst the workflow tasks performed by different collaborating domains are verified.

We propose and evaluate techniques to manage disk storage systems for multimedia document servers with constrained I/O resources. We also evaluate the requirements for the main memory to maintain desired levels of quality of presentation (QoP) for multiple users. This is achieved by attempting to minimize the number of tardy frames in end-to-end delivery of multimedia data. Inter-media and intra-media temporal synchronization at the user-interaction level are essential concerns for multimedia servers. Scheduling of multimedia frames has direct impact on both intra-stream and inter-stream multimedia synchronization. In order to effect such synchronization, we propose several O(n log n+mn) heuristics to schedule multimedia frames between the disks and destination memories of the multimedia systems, where m is the number of logical I/O channels and n is the number of frames of multimedia data. We study the performance of these heuristics via simulations and show the tradeoffs between the system resources and QoP parameters.

The construction and maintenance of large, high-quality software projects is a complex, error-prone and difficult process. Tools employing software database metrics can play an important role in the efficient execution and management of such large projects. In this paper, we present a generic framework to address this problem. This framework incorporates database and knowledge-base tools, a formal set of software test and evaluation metrics, and a suite of advanced analytic techniques for extracting information and knowledge from available data. The proposed combination of critical metrics and analytic tools can enable highly efficient and cost-effective management of large and complex software projects. The framework has the potential for greatly reducing venture risks and enhancing production quality in the domain of large-scale software project management.

Distributed, networked multimedia information systems will be a critical component of technology-based information infrastructures in the future. Several ground-breaking applications have already appeared, and more are many are expected to follow. Innovations in hardware and software are feeding this revolution. In this paper, the notion of "quality of presentation" (QOP) for multimedia data transferred over the networks is developed. Multimedia data synchronization requirements are studied, and several synchronization protocols are presented. We discuss the management of pre-orchestrated as well as live multimedia data. It is anticipated that, with proper research breakthroughs, broadband multimedia networking technologies will bring about spectacular changes in the ways that we store, process and use information.

We present a framework for managing large software projects using metrics. The collection and analysis of metrics data serve as a consistent mechanism for risk identification and quality management. The crux of this mechanism is the temporal modeling of metrics data. We present a comprehensive set of temporal operators which serve as the building block for the formal specification of users' views of risk and quality. The notion of temporal inheritance can be used to define an object oriented query language.

Distributed, networked multimedia information systems will be a critical component of technology-based information infrastructures in the future. We present an infrastructure for supporting multimedia applications. We discuss various characteristics of multimedia data and the effect of the network on the required quality of presentation for multimedia data. We present a suite of synchronization protocols to support the quality of presentation. The crux of these protocols is the scheduling of multimedia information for synchronized delivery, over broadband networks with limited resources, and is identified as an NP-hard problem. We introduce two parameters which can be used to measure the performance of end-to-end synchronization protocols in a network supporting distributed multimedia applications. We propose and implement several heuristic scheduling algorithms, and compare their performance. We deduce the appropriateness of these algorithms in different types of distributed multimedia environments.

Discusses issues related to the design and and usage of database management systems consisting of massive amounts of data in parallel environments. The issues include the placement of the data in the memory, file systems, concurrent access to data, effects on query processing, the implications of specific machine architectures, and the peculiarities of specific parallel systems. Since not all parameters are currently amenable to rigorous analysis, results of performance studies are highlighted wherever they are deemed appropriate. >

Discusses the current state-of-the-art issues in multimedia database management systems. The most important aspect of data management is the semantic modeling and indexing of multimedia information. We discuss various schemes to represent temporal synchronization requirements and highlight current research challenges facing the multimedia database community.>