5408151
Alternative Objects in Object-oriented Databases
44800514
Logical Integration of Locally Independent Relational Databases into a Distributed Database
This paper discusses a constraint integration problem, which occurs in constructing a global view of a distributed database by local relational databases. Each local database has its own semantic constraints. such as functional, join and embedded join dependencies (FDs. JDs and EJDs, respectively). A global view of a distributed database is assumed to be defined by taking a join of these local databases. Some dependency constraints on a local database may be violated on a global view. 
 
In this paper, we show (a) the relationship between dependencies of local databases and dependencies appearing in a global view, (b) a testing method whether an EJD appears in a global view when only FDs and JDs are given to each local database, end (c) some conditions for a JD of a local database to appear in a global view as an EJD.
22236580
OVID: Design and Implementation of a Video-Object Database System
A video-object data model and the design and implementation of a prototype video-object database system named OVID based on the model are described. Notable features of the video-object data model are a mechanism to share common descriptional data among video-objects, called interval-inclusion based inheritance, and operations to composite video-objects. The OVID system offers a browsing/inspection tool called VideoChart, and adhoc query facility called VideoSQL, and a video-object definition tool. >
18193868
Interval Queries on Object Histories: Extended Abstract
This extended abstract introduces the notion of ’ interval queries ’ on historical data for objects (here, called ‘object histories’) and explores a certain closure property. As for describing historical data for objects, we use our mathematical model introduced in our earlier paper. The major construct in the model is a ‘computation-tuple sequence scheme’ (abbreviated CSS), which specifies the set of all possible ‘valid’ object histories for the same type of object. Interval queries are those queries which return an interval (history) from a given object history. We provide conditions under which an interval query applied to object histories described by one CSS yields, as its answers. the set of all object histories which can be described by another CSS.
36124114
Schema virtualization in object-oriented databases
A description is given of the concept and implementation techniques of schema virtualization in object-oriented databases. The objective of schema virtualization is to provide users with multiple views of a database. First, the notions of virtual classes and virtual schemata, which are natural extension of views in relational databases, is introduced. Then, procedures to convert a schema into a virtual one, as well as rules schemata and their conversion should satisfy, are discussed. The key issue of the design of virtual classes and virtual schemata is 'regarding procedures as objects'. Closure properties of classes and schemata are also discussed. Finally, several implementation techniques for realizing schema virtualization in Smalltalk-80 are presented.<<ETX>>
5205647
Problems of Relational Database Design
In the logical design of a relational database, the theory of data dependencies has been playing an important role. Data depenencies are integrity constraints concerned with attribute relationships. The theory of functional dependencies (FDs) were successful to capture the important aspects of relational database design: semantics of data and logical scheme design (normalization). Several problems of FDs have been also pointed out, and many kinds of new dependencies have been introduced as the generalizations of FDs. Each of the researches on the theory of the new dependencies, semantics of data and the logical scheme design has made a great progress with few sufficient interactions. This leads to several problems when the data dependency theory is used in the actual relational database design.
120935286
Automatic hyperparameter estimation in probabilistic image restoration algorithm based on Gibbs microcanonical distribution
For an original image given as an 8-gray-level image, the framework for image restoration is composed of Bayes statistics for the a priori probability distribution based on the microcanonical distribution. In this process, the a priori probability distribution serving as the microcanonical distribution is formulated on the basis of the variables characterizing the spatial flatness and smoothness of the image in terms of the number of nearest pixel pairs with different gray levels and the number of nearest pixel pairs with gray levels differing by 1. In the present paper, we propose a new method of estimation, from a degraded image, of the number of nearest pixel pairs with different gray levels and the number of nearest pixel pairs with gray levels differing by 1 in the original image. Then, based on that formulation, an iterative computation algorithm for the restoration of a 256-gray-level image is presented from the viewpoint of statistical mechanics. Through some numerical experiments, we investigate how the proposed method can improve the quality of the restored image. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 36(1): 68–78, 2005; Published online in Wiley InterScience (). DOI 10.1002sscj.10365
3247078
Individual Level Analysis Using Decision Making Features in Multiagent Based Simulation
We introduce a set of evaluation tools in the framework of individual level analysis for multiagent based simulations. These tools are intended to overcome the weak points of multiagent systems: that it is difficult to avoid mistakes in description and arbitrary modeling; and to find reliable explanations of causal relationships between the model and its result. We analyze some artificial market models using an evaluation process that consists of the evaluation of initial learning maturity, discrimination between models, and the visualization of attention tendency in a group. We conclude that these analytical methods are useful for the evaluation of multiagent based simulations in terms of validation and finding causal relations.
18847598
A method for panoramic stereo image acquisition
One of the key technologies for one-to-many visual communication is panoramic stereo, in which stereoscopic images for arbitrary horizontal directions are presented to multiple users, according to their positions and postures. In this paper, one of the methods for capturing panoramic stereo motion pictures is proposed and evaluated, along with an experimentation. Through preliminary experimentation, we have confirmed the effectiveness of methods using a curved mirror.
16332479
Preferential Urn Model on a Random Network
A preferential urn model on a random network and a complete graph is studied. The preferential urn model is based on the concept "the rich get richer", and has simple dynamics of ball-transfers. The model is considered as a simple socio-economic system. From analytical treatments, it has been revealed that the preferential urn model on the complete graph gives a fat-tailed occupation distribution in the case with randomness for fitness parameters. In the present paper, using numerical experiments, we show that the model on the random network gives a fat-tailed occupation distribution in the case without randomness for fitness parameters; hence, we would consider that the local ball-transfer process on the random network includes effects corresponding to the randomness for fitness parameters. This simple game would give a valuable insight into various phenomena from socio-economic point of view
43363560
Adaptive Dynamic Voltage Scaling for Real-Time Systems