QUERY EVALUATION IN PARTITIONED DISJUNCTIVE DEDUCTIVE DATABASES

1994 ◽  
Vol 03 (04) ◽  
pp. 385-413 ◽  
Author(s):  
ADNAN YAHYA ◽  
JACK MINKER
Keyword(s):  
Query Processing ◽  
Evaluation Process ◽  
Deductive Databases ◽  
Deductive Database ◽  
Query Evaluation ◽  
Disjunctive Deductive Databases ◽  
Special Cases ◽  
The Individual

Query evaluation in disjunctive deductive databases is in general computationally hard. The class of databases for which the process is tractable is severely limited. The complexity of the process depends on the structure of the database as well as on the type of query being evaluated. In this paper we study the issue of simplified query processing in disjunctive deductive databases. We address the possibility of evaluating general queries by independently processing their atomic components and describe the class of databases for which this approach is possible. We also discuss the issue of dividing a disjunctive deductive database into a set of disjoint components then answering queries and computing database completions by combining the results obtained against the individual components. Some practical special cases are considered. The methods developed in this paper can be utilized to introduce parallelism into the query evaluation process.

Querying Issues in Pervasive Environments

2011 ◽  
pp. 1-23
Author(s):  
Genoveva Vargas-Solar ◽  
Noha Ibrahim ◽  
Christine Collet ◽  
Michel Adiba ◽  
Jean Marc Petit ◽  
...  
Keyword(s):  
Query Processing ◽  
Service Composition ◽  
Moving Objects ◽  
Evaluation Process ◽  
Continuous Queries ◽  
Query Evaluation ◽  
Pervasive Environments ◽  
General Overview ◽  
Existing Data

The main objective of this chapter is to present a general overview of existing approaches on query processing and the authors’ vision on query evaluation in pervasive environments. It illustrates, with scenarios and practical examples, existing data and streams querying systems in pervasive environments. It describes the evaluation process of (i) mobile queries and queries on moving objects, (ii) continuous queries and (iii) stream queries. Finally, the chapter introduces the authors’ vision of query processing as a service composition in pervasive environments.

Optimal Consumption and Insurance: A Continuous-time Markov Chain Approach

2008 ◽  
Vol 38 (01) ◽  
pp. 231-257 ◽  
Author(s):  
Holger Kraft ◽  
Mogens Steffensen
Keyword(s):  
Continuous Time ◽  
Optimal Solution ◽  
Decision Problems ◽  
Optimal Consumption ◽  
Continuous Time Markov Chain ◽  
Financial Decision Making ◽  
Markov Chain Approach ◽  
Special Cases ◽  
Financial Decision ◽  
The Individual

Personal financial decision making plays an important role in modern finance. Decision problems about consumption and insurance are in this article modelled in a continuous-time multi-state Markovian framework. The optimal solution is derived and studied. The model, the problem, and its solution are exemplified by two special cases: In one model the individual takes optimal positions against the risk of dying; in another model the individual takes optimal positions against the risk of losing income as a consequence of disability or unemployment.

Bayesian Prediction in Hybrid Conjoint Analysis

2002 ◽  
Vol 39 (2) ◽  
pp. 253-261 ◽  
Author(s):  
Frenkel Ter Hofstede ◽  
Youngchan Kim ◽  
Michel Wedel
Keyword(s):  
Prior Information ◽  
Current Model ◽  
The Self ◽  
Attribute Importance ◽  
Individual Level ◽  
Special Cases ◽  
Full Profile ◽  
Credible Intervals ◽  
Competing Models ◽  
The Individual

The authors propose a general model that includes the effects of discrete and continuous heterogeneity as well as self-stated and derived attribute importance in hybrid conjoint studies. Rather than use the self-stated importances as prior information, as has been done in several previous approaches, the authors consider them data and therefore include them in the formulation of the likelihood, which helps investigate the relationship of self-stated and derived importances at the individual level. The authors formulate several special cases of the model and estimate them using the Gibbs sampler. The authors reanalyze Srinivasan and Park's (1997) data and show that the current model predicts real choices better than competing models do. The posterior credible intervals of the predictions of models with the different heterogeneity specifications overlap, so there is no clear superior specification of heterogeneity. However, when different sources of data are used—that is, full profile evaluations, self-stated importances, or both—clear differences arise in the accuracy of predictions. Moreover, the authors find that including the self-stated importances in the likelihood leads to much better predictions than does considering them prior information.

Vocational Evaluation in a Forensic Psychiatric Setting

1986 ◽  
Vol 53 (1) ◽  
pp. 31-35 ◽  
Author(s):  
Chris Lloyd
Keyword(s):  
Evaluation Process ◽  
Occupational Therapists ◽  
Work History ◽  
Evaluation Systems ◽  
Psychiatric Setting ◽  
Vocational Evaluation ◽  
Individual Client ◽  
Commercial Work ◽  
Forensic Psychiatric ◽  
The Individual

The Forensic Unit of the Alberta Hospital Edmonton has moved from evaluating the performance of a client in a work setting by observation to providing a comprehensive data base on the client through the use of a work history, interest screening and commercial work evaluation systems. A standardized approach, to evaluation has enabled the Occupational Therapists to develop a unique treatment programme for the individual client as a result of the evaluation process and provided reliable data in returning the client to competitive employment.

Adaptive linear list reorganization under a generalized query system

1995 ◽  
Vol 32 (03) ◽  
pp. 793-804 ◽  
Author(s):  
R. S. Valiveti ◽  
B. J. Oommen ◽  
J. R. Zgierski
Keyword(s):  
Simple Model ◽  
Query Processing ◽  
Generation Mechanism ◽  
Linear List ◽  
Query Generation ◽  
Query System ◽  
The Individual

We consider the problem of reorganizing a linear list, when the individual queries consist of accesses to a subset of the elements stored, as opposed to the individual elements themselves. In this paper, which to our knowledge represents the first reported result in this model of query processing, we first propose a simple model for a query generator which emits set queries. Subsequently, we present extensions to the classical move-to-front (MTF) and transposition (TR) rules under this generalized query generation mechanism and analyze their performance.

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