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.
29360261
Towards Abstracting Complex Database Objects: Generalization, Reduction and Unification of Set-type Objects (Extended Abstract)
Representing and manipulating complex (database) objects are important issues in the semantic database models and object-oriented database models, most of which have a rich expressive power for complex objects. In this paper, we will focus on the manipulation of complex objects, and introduce the notions and the operations for abstracting complex objects. We introduce the notion of "element-based" generalization relationships between complex objects, and two new abstraction operators: reduction and unification. Their algebraic properties are then formally investigated especially for "set-type" complex objects.
46335278
Tree-Structured Data Organization with Consecutive Retrieval Property
COMP2011 Aleksandar Ignjatovic 2005 c 2 Figure 1: A medieval copy of arguably the most influential textbook ever written, Eu-clid's Elements (Στoι χε´ια), from about 300 BC. It contains the oldest known algorithm recorded, Euclid's algorithm for computing the Greatest Common Divisor (GCD) of two natural numbers. Figure 2: First data structures: a Mesopotamian cuneiform tablet from about 3000 BC with an inventory list. Preface This booklet is not meant to be a textbook, but only a companion to the textbook that we use in this course, Cormen, Leiserson, Rivest and Stein's Introduction to Algorithms, the second edition. Its purpose is to help you read the appropriate sections of the textbook, and integrate it better with the rest of the course. It also adds a number of exercises not present in the textbook. Please read the textbook and do not rely on this supplement only.
32965529
Interval Queries on Object Histories
Abstract The present paper introduces the notion of “interval queries” on object histories and explores a certain closure property. In particular, conditions are provided under which an interval query applied to object histories described by one “computational-tuple sequence scheme” (CSS) yields, as its answer, the set of all object histories which can be described by another CSS.
205099974
Organization of quasi-consecutive retrieval files
Abstract In 1972, Ghosh introduced the consecutive retrieval (CR) file organization. It is an efficient file organization in which all records pertinent to a query are consecutively stored on linear storage locations. In this paper, we introduce the quasi-consecutive retrieval (QCR) file organization. The QCR file organization is an extension of Ghosh's CR file organization and normally offers less redundancy. In the QCR file, all the records pertinent to each query are not necessarily stored consecutively, but rather they are stored within an area of the buffer size. In this paper, we discuss graph theoretic properties of CR files and QCR files by using the properties of interval graphs well known in graph theory. We provide a basic condition for the existence of a QCR file without redundancy for a given buffer size. By introducing redundant queries, such a condition is simplified. Furthermore, a heuristic computer algorithm is given to organize a QCR file with less redundancy for a given buffer size.
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.
11983347
Linear Response Formula in Generalized Belief Propagation for Probabilistic Inference
Linear response formulas for the generalized belief propagation in approximate inference are derived by using generalized belief propagation. The linear response formulas can give us the marginal probability between every pair of nodes and we obtain good accuracy in some examples of practical probabilistic inferences
26636790
TWISTER: an immersive autostereoscopic display
This paper describes in detail the design, development, and evaluation of the TWISTER III (Telexistence Wide-angle Immersive STEReoscope) and demonstrates how this system can display immersive three-dimensional full-color and live motion pictures without the need for special eye-wear. The device works as a cylindrical display by rotating 30 display units around an observer and presenting time-varying patterns, while immersive autostereoscopic vision is achieved by employing a "rotating parallax barrier" method. After explaining the principle, we discuss the designs and implementations for maximum performance in various aspects of the display. We also evaluate the display.
35660731
Some Properties of Fuzzy Sets of Type 2
The concept of fuzzy sets of type 2 has been defined by L. A. Zadeh as an extension of ordinary fuzzy sets. The fuzzy set of type 2 can be characterized by a fuzzy membership function the grade (or fuzzy grade) of which is a fuzzy set in the unit interval [0, 1] rather than a point in [0, 1]. This paper investigates the algebraic structures of fuzzy grades under the operations of join ⊔, meet ⊔, and negation ┐ which are defined by using the extension principle, and shows that convex fuzzy grades form a commutative semiring and normal convex fuzzy grades form a distributive lattice under ⊔ and ⊓. Moreover, the algebraic properties of fuzzy grades under the operations and which are slightly different from ⊔ and ⊓, respectively, are briefly discussed.
8895020
The strong soundness theorem for real closed fields and Hilbert’s Nullstellensatz in second order arithmetic
Abstract.By RCA0, we denote a subsystem of second order arithmetic based on Δ01 comprehension and Δ01 induction. We show within this system that the real number system R satisfies all the theorems (possibly with non-standard length) of the theory of real closed fields under an appropriate truth definition. This enables us to develop linear algebra and polynomial ring theory over real and complex numbers, so that we particularly obtain Hilbert’s Nullstellensatz in RCA0.
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