By Topic

Knowledge and Data Engineering, IEEE Transactions on

Issue 4 • Date Jul/Aug 1997

Filter Results

Displaying Results 1 - 14 of 14
  • Programming with logical queries, bulk updates, and hypothetical reasoning

    Page(s): 587 - 599
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (204 KB)  

    The paper presents a language of update programs that integrates logical queries, bulk updates and hypothetical reasoning in a seamless manner. There is no syntactic or semantic distinction between queries and updates. Update programs extend logic programs with negation in both syntax and semantics. They allow bulk updates in which an arbitrary update is applied simultaneously for all answers of an arbitrary query. Hypothetical reasoning is naturally supported by testing the success or failure of an update. We describe an alternating fixpoint semantics of update programs and show that it can express all nondeterministic database transformations View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The NUMA with clusters of processors for parallel join

    Page(s): 653 - 660
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (240 KB)  

    A number of hybrid systems have been proposed to combine the advantages of shared nothing and shared everything concepts for computing relational join operations. Most of these proposed systems, however, presented a few analytical results and have produced limited or no implementations on actual multiprocessors. In this paper, we present a parallel join algorithm with load-balancing for a hybrid system that combines both shared-nothing and shared-everything architectures. We derive an analytical model for the join algorithm on this architecture and validate it using both hardware/software simulations and actual experimentations. We study the performance of the join on the hybrid system for a wide range of system parameter values. We conclude that the hybrid system outperforms both shared-nothing and shared-everything architectures View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multiprocessor document allocation: a genetic algorithm approach

    Page(s): 640 - 642
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (44 KB)  

    We formally define the Multiprocessor Document Allocation Problem (MDAP) and prove it to be computationally intractable (NP complete). Once it is shown that MDAP is NP complete, we describe a document allocation algorithm based on genetic algorithms. This algorithm assumes that the documents are clustered using any one of the many clustering techniques. We later show that our allocation algorithm probabilistically converges to a good solution. For a behavioral evaluation, we present sample experimental results View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On a pattern-oriented model for intrusion detection

    Page(s): 661 - 667
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (220 KB)  

    Operational security problems, which are often the result of access authorization misuse, can lead to intrusion in secure computer systems. We motivate the need for pattern-oriented intrusion detection, and present a model that tracks both data and privilege flows within secure systems to detect context-dependent intrusions caused by operational security problems. The model allows the uniform representation of various types of intrusion patterns, such as those caused by unintended use of foreign programs and input data, imprudent choice of default privileges, and use of weak protection mechanisms. As with all pattern-oriented models, this model cannot be used to detect new, unanticipated intrusion patterns that could be detected by statistical models. For this reason, we expect that this model will complement, not replace, statistical models for intrusion detection View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A transparent schema-evolution system based on object-oriented view technology

    Page(s): 600 - 624
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (740 KB)  

    When a database is shared by many users, updates to the database schema are almost always prohibited because there is a risk of making existing application programs obsolete when they run against the modified schema. The paper addresses the problem by integrating schema evolution with view facilities. When new requirements necessitate schema updates for a particular user, then the user specifies schema changes to his personal view, rather than to the shared base schema. Our view schema evolution approach then computes a new view schema that reflects the semantics of the desired schema change, and replaces the old view with the new one. We show that our system provides the means for schema change without affecting other views (and thus without affecting existing application programs). The persistent data is shared by different views of the schema, i.e., both old as well as newly developed applications can continue to interoperate. The paper describes a solution approach of realizing the evolution mechanism as a working system, which as its key feature requires the underlying object oriented view system to support capacity augmenting views. We present algorithms that implement the complete set of typical schema evolution operations as view definitions. Lastly, we describe the transparent schema evolution system (TSE) that we have built on top of GemStone, including our solution for supporting capacity augmenting view mechanisms View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Feature selection via discretization

    Page(s): 642 - 645
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (48 KB)  

    Discretization can turn numeric attributes into discrete ones. Feature selection can eliminate some irrelevant and/or redundant attributes. Chi2 is a simple and general algorithm that uses the χ 2 statistic to discretize numeric attributes repeatedly until some inconsistencies are found in the data. It achieves feature selection via discretization. It can handle mixed attributes, work with multiclass data, and remove irrelevant and redundant attributes View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Intelligent critic system for architectural design

    Page(s): 625 - 639
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (492 KB)  

    The paper describes an intelligent computer aided architectural design system (ICAAD) called ICADS. ICADS encapsulates different types of design knowledge into independent “critic” modules. Each “critic” module possesses expertise in evaluating an architect's work in different areas of architectural design and can offer expert advice when needed. This research focuses on the representation of spatial information encoded in architectural floor plans and the representation of expert design knowledge. Described in the paper is our research in designing and developing two particular “critic” modules. The first module, FPDX, checks a residential apartment floor plan, verifies that the plan meets a set of government regulations, and offers suggestions for floor plan changes if regulations are not met. The second module, IDX, analyzes room and furniture layout according to a set of interior design guidelines and offers ideas on how furniture should be moved if the placement does not follow good design principles View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Cell suppression methodology: the importance of suppressing marginal totals

    Page(s): 513 - 523
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (216 KB)  

    Safeguarding confidential information is of paramount concern to government agencies in publishing statistical data. Given a set of sensitive cells, the problem is to identify a set of complementary cells to suppress so as to mask the values of the sensitive cells. All of the existing cell suppression methods fail to consider the relationships among cell values and the representation of these relationships in marginal totals. That marginal totals may contain potent information has not been appreciated. The paper employs the theory of nominal data analysis to demonstrate that the disclosure of marginal totals can be very risky. It recommends adding a front end test to the existing methods. The goal is to identify a list of sensitive marginal totals that have to be suppressed. This increases the sophistication of cell suppression methodology by providing an extra layer of protection View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Authorization and revocation in object-oriented databases

    Page(s): 668 - 672
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (44 KB)  

    Few studies of object-oriented databases deal with their security, a fundamental aspect of systems with complex data structures. Most authorization systems give users who own resources only some basic control over them; here, we provide users with more direct control over their resources by associating with each grant propagation numbers. Propagation numbers govern the grantability and exercisability of the privileges. Of particular interest in our study of authorization in an OO environment is the combination of inheritance and granting of privileges. Diverse policies are discussed and implemented in a test-bed system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A deductive environment for dealing with objects and nonmonotonic reasoning

    Page(s): 539 - 558
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (492 KB)  

    The Bottom-up Query machine (BQM)-the role played by our system in the framework of the KIWIS system (K. Apt et al., 1987)-extends deductive database technology with knowledge structuring capabilities to provide an advanced environment for the development of data and knowledge based applications. The system relies on a knowledge representation language that combines the declarativeness of logic programming with the notions of object, inheritance with exceptions, and message passing. Exceptions are supported by allowing rules with negated heads. The use of exceptions inside the inheritance mechanism makes the language inherently nonmonotonic. The paper contains a comprehensive description of both the language and the implementation principles of the BQM system. It begins by providing a model theoretic semantics of the language based on the notion of least model. A fixpoint semantics, providing a constructive definition of the least model, is given as well. Then, a number of implementation techniques for efficient query evaluation are described. Such techniques significantly extend “traditional” deductive database query evaluation strategies to deal with monotonic reasoning. A description of the architecture of the current prototype of the BQM system is also given View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Establishing the relevancy of the bookkeeping libraries to the functional testing of computer implementations

    Page(s): 646 - 652
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (56 KB)  

    We address issues related to the definition of faults, errors and failures and their separability, and attribution to the different development processes of computing systems. In particular, we deal with historical databases, which presumably contain certain data (i.e., test failure data) and describe the methodology that can be used to analyze the database and obtain the pertinent information. The validation method may be of particular importance, especially when information from the database needs to be extrapolated for a purpose other than the one for which the database was developed. Our methodology was used to evaluate the historical data collected during the development of the IBM 4381 and 9370 family of computers, and to extrapolate the faults found during the function testing View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Information flow control in object-oriented systems

    Page(s): 524 - 538
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB)  

    We describe a high assurance discretionary access control model for object oriented systems. The model not only ensures protection against Trojan horses leaking information, but provides the flexibility of discretionary access control at the same time. The basic idea of our approach is to check all information flows among objects in the system in order to block possible illegal flows. An illegal flow arises when information is transmitted from one object to another object in violation of the security policy. The interaction modes among objects are taken into account in determining illegal flows. We consider three different interaction modes that are standard interaction modes found in the open distributed processing models. The paper presents formal definitions and proof of correctness of our flow control algorithm View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An empirical study of domain knowledge and its benefits to substructure discovery

    Page(s): 575 - 586
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (500 KB)  

    Discovering repetitive, interesting, and functional substructures in a structural database improves the ability to interpret and compress the data. However, scientists working with a database in their area of expertise often search for predetermined types of structures or for structures exhibiting characteristics specific to the domain. The paper presents a method for guiding the discovery process with domain specific knowledge. The SUBDUE discovery system is used to evaluate the benefits of using domain knowledge to guide the discovery process. Domain knowledge is incorporated into SUBDUE following a single general methodology to guide the discovery process. Results show that domain specific knowledge improves the search for substructures that are useful to the domain and leads to greater compression of the data. To illustrate these benefits, examples and experiments from the computer programming, computer aided design circuit, and artificially generated domains are presented View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Implementation of tabled evaluation with delaying in Prolog

    Page(s): 559 - 574
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (452 KB)  

    Unlike SLD resolution as implemented in Prolog, tabled evaluation with delaying guarantees termination for function free logic programs, avoids repeated computation of identical subqueries, and handles recursion through negation. It is often used in query processing and nonmonotonic reasoning where termination is required. The paper presents a new technique for incorporating tabled evaluation into existing Prolog systems. It requires neither time consuming modifications of a Prolog engine nor metainterpretation that can enormously slow down program execution. Instead, using a program transformation approach, the technique allows effective use of the advanced Prolog technology. The transformed program uses tabling primitives implemented externally in C that provide direct control over the search strategies. This brings efficiency as well as portability across Prolog systems. Experiences with a prototype implementation indicate that the approach results in a flexible and pragmatic method for query processing and nonmonotonic reasoning on top of Prolog. Performance measurements show that the method is efficient for practical applications View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

IEEE Transactions on Knowledge and Data Engineering (TKDE) informs researchers, developers, managers, strategic planners, users, and others interested in state-of-the-art and state-of-the-practice activities in the knowledge and data engineering area.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Jian Pei
Simon Fraser University