In this paper, we describe the problem of recommending conference sessions to attendees and show how novel extensions to traditional model-based recommender systems, as suggested in Adomavicius and Tuzhilin [CHECK END OF SENTENCE], can address this problem. We introduce Recommendation Engine by CONjoint Decomposition of ITems and USers (RECONDITUS)-a technique that is an extension of preference-based recommender systems to recommend items from a new disjoint set to users from a new disjoint set. The assumption being that preferences exhibited by users with known usage behavior (e.g., past conference session attendance), which can be abstracted by projections of user and item matrices, will be similar to ones of new (different) users where the basic environment and item domain are the same (e.g., new conference). RECONDITUS requires no item ratings, but operates on observed user behavior such as past conference session attendance. The RECONDITUS paradigm consists of projections of both user and item data, and the learning of relationships in projected space. Once established, the relationships enable predicting new relationships and provide associated recommendations. The approach can encompass several traditional data mining problems where both clustering and prediction are necessary. RECONDITUS has been evaluated using data from the Oracle OpenWorld conference.

A Transaction Specification and Management Environment (TSME) is a programmable system that supports implementation-independent specification of application-specific extended transaction models (ETMs) and configuration of transaction management mechanisms (TMMs) to enforce specified ETMs. The TSME can ensure correctness and reliability while allowing the functionality required by workflows and other advanced applications that require access to multiple heterogeneous, autonomous, and/or distributed (HAD) systems. To support ETM specification, the TSME provides a transaction specification language that describes dependencies between transactions. Unlike other ETM specification languages, TSME's dependency descriptors use a common set of primitives, and are enforceable, i.e., can be evaluated at any time during transaction execution to determine whether operations issued violate ETM specifications. To determine whether an ETM can be enforced in a specific HAD system environment, the TSME supports specification of the transactional capabilities of HAD systems, and comparison of these with ETM specifications to determine mismatches. To enforce ETMs that are more restrictive than those supported by the union of the transactional capabilities of HAD systems, the TSME provides a collection of transactional services. These services are programmable and configurable, i.e., they accept instructions that change their behavior as required by an ETM and can be combined in specific ways to create a run-time TMM capable of enforcing the ETM. We discuss the TSME in the context of a distributed object management system. We give ETM specification examples and describe corresponding TMM configurations for a telecommunications application.

A Transaction Specification and Management Environment (TSME) is a transaction processing system toolkit that supports the definition and construction of application-specific extended transaction models (ETMs). The TSME provides a transaction specification language that allows a transaction model designer to create implementation-independent specifications of extended transactions. In addition, the TSME provides a programmable transaction management mechanism that assembles and configures a run-time environment to support specified ETMs. The authors discuss the TSME in the context of a distributed object management system (DOMS), and describe specifications of extended transactions and corresponding configurations of transaction management mechanisms.>

A variety of extensions to the traditional (ACID) transaction model have resulted in a plethora of extended transaction models (ETMs). Many of these ETMs are application-specific, i.e. they are designed to provide correctness guarantees adequate for a particular application, but not others. Similarly, an application-specific ETM may impose restrictions that are unacceptable in one application, yet required in another. To define new ETMs, to determine whether an ETM is appropriate for an application, and to integrate ETMs to produce new ETMs, we need a framework for ETM specification and reasoning. In this paper, we describe such a framework. Our framework supports implementation-independent specification of ETMs described in terms of dependencies between transactions. Dependencies are specified using dependency descriptors. Unlike other transaction specification frameworks, dependency descriptors use a common set of primitives, and are enforceable, i.e. can be evaluated at any time during transaction execution to determine whether issued operations violate ETM specifications. We discuss specifications of (i) structure dependencies between transaction states, and (ii) correctness dependencies for serializability, various cooperative and temporal correctness criteria, and recoverability. We give ETM specification examples for a telecommunications application illustrating the definition of a new application-specific ETM using our framework.

Future information processing environments will consist of a vast network of heterogeneous, autonomous, and distributed computing resources, including computers (from mainframe to personal), information-intensive applications, and data (files and databases). A key challenge in this environment is providing capabilities for combining this varied collection of resources into an integrated distributed system, allowing resources to be flexibly combined, and their activities coordinated, to address challenging new information processing requirements. In this paper, we describe the concept of distributed object management, and identify its role in the development of these open, interoperable systems. We identify the key aspects of system architectures supporting distributed object management, and describe specific elements of a distributed object management system being developed at GTE Laboratories.

This paper describes the basic data model of an object-oriented database and the basic architecture of the system implementing it. In particular, a secondary storage segmentation scheme and a transaction-processing scheme are discussed. The segmentation scheme allows for arbitrary clustering of objects, including duplicates. The transaction scheme allows for many different sharing protocols ranging from those that enforce serializability to those that are nonserializable and require communication with the server only on demand. The interaction of these two features is described such that segment-level transfer and object-level locking is achieved.