This paper proposes the concept of information retrieval for fine arts database system on the fuzzy set theory, especially concerning to sensitive impression and location data. The authors have already reported several important formulations about the data structure and information retrieval models based on the fuzzy set theory for multimedia database. The fuzzy models of the information retrieval are implemented in the fine arts database system, which has the following features: (1) The procedure of information retrieval is formulated in the fuzzy set theory; (2) This database can treat multimedia data such as document data, sensitive impression, location information, and imagedata. (3) It is possible to retrieve the stored data based on sensitive impression and the location data such as "joyful pictures which have a mountain in the center and there is a tree in the right"; (4) Users can input impression words as a retrieval condition, and estimate their grades such as "low," "medium," and "high"; (5) For the result of information retrieval, the satisfaction grade is calculated based on fuzzy retrieval model; and (6) The stored data are about 400 fine arts paintings which are inserted by the textbook of fine arts currently used at the junior high school and high school in Japan. These features of this system give an effects of the fine arts education, and should be useful for information retrieval of fine arts. The results of this study will become increasingly important in connection with development of multimedia technology.

The join operation is one of the most expensive operations in relational database systems. So far many researchers have proposed several hash-based algorithms for the join operation. In a hash-based algorithm, a large relation is first partitioned into several clusters. When clusters overflow, that is, when the size of the cluster exceeds the size of main memory, the performance of hash-based algorithms degrade substantially. Previously we proposed the GN hash algorithm which is robust in the presence of overflown clusters. The GN hash join algorithm combines the Grace hash join and hash-based nested-loop join algorithms. We analyze the performance of the GN hash join algorithm when applied to relations with a non-uniform Zipf-like data distribution. The performance is compared with other hash-based join algorithms: Grace, Hybrid, nested-loop, and simple hash join. The GN hash join algorithm is found to have higher performance on non-uniformly distributed relations. In this paper, the robustness of the GN hash algorithm from the point of choosing a run time method is verified. In the GN hash algorithm, the criterion for selecting a run time method from the two algorithm is determined by using the value calculated from the I/O cost formula of the two algorithms. This criterion cannot be guaranteed to be optimal under every data distribution, that is, the optimal criterion may change depending on the data distribution. When the data distribution is unknown, all data has to be repartitioned in order to get an accurate optimal criterion. However, from the view of choosing a method at run time, it is necessary for the GN hash algorithm to determine an appropriate criterion regardless of the data distribution. Thus, we inspect the criterion adopted in our algorithm under a simulation environment. From simulation results, we find that the range of the criterion is very wide under any data distribution and assure that the criterion determined with the assumption of a uniform data distribution can be used even when the data is highly skewed. Consequently, we can conclude that the GN hash algorithm which dynamically selects the nested-loop and Grace hash algorithms provides good performance in the presence of data skew and its performance is not sensitive to the criterion.

In retrieving information from databases widely distributed in a network, the first thing to do is to search and find the database where the required information is stored. We call this the information searches rather than the retrievals. In this paper, we present a search and retrieval method for multimedia information, especially images. First, we formalize the general elements of information search and introduce a new search concept based on entropy reduction. Next, we discuss recent new technologies for image retrieval and introduce a new image retrieval system called VideoReality. Third, we present several methods of searching in the network- for example, the Internet robot TITAN, and a new search method for images distributed in the network that is based on the hierarchical structure of image retrieval. Finally, we discuss the network control and design concepts appropriate for information search and retrival.

Intending to contribute to constructing better multimedia network systems, we propose a new concept of image database system of which form of storage is featuring exponential or graceful oblivion and abrupt recollection like the human memory property. By virtue of this property of database storages that is realized by employing hierarchical or pyramidal image coding, the database memory and transmission costs can be significantly reduced. In this paper we will describe the details of the concept, the results of theoretical analysis based on a simplified model which reveals the effectiveness of the proposed system, the structure of an experimental prototype system and the result of an experimental image retrieval service carried out by implementing it over ATM high speed channels.

In this paper, we propose a timing constrained database system which accesses a database at a host computer via a mobile support server with a wireless portable computer running in mobile computing environments, so that we can provide seamless database access between a communication cell and the host computer even if the user of the portable computer moves from one communication cell to another. Then, we also provide some new kind of database cache algorihm, such as all-cell-cache, neighbour-cell-cache, 1-cell-skip-cache, 2-cell-skip-cache and 3-cell-skip-cache methods, each of which manages the data downloading and uploading among the host database and some cell databases at the mobile support servers so as to minimize the database access fault probability when the user moves from one communication cell to another. And, we show the averaged database access time and the averaged database cache hit ratio which are computed by simulating each of the above database cache algorithms with random variables generation method. Finally, we conclude that each above cache alogorithm is advantageous to the database in mobile computineg einvironments.

The purposes of the current PE92 database project are twofold. One is to provide raw data to researchers so that they can concentrate their efforts primarily on the development of character recognition algorithms. The other is to provide a standard handwritten character data set to the perspective users as well as the developers so that they can evaluate and compare the performance of character recognition systems objectively. We collected 100 handwritten image sets of 2,350 Hanguel characters that correspond to the character set specified in Korean Standards KSC5601-1987 computer codes. We tried to collect as many writing styles as possible. The first 70 sets were generated by more than 500 different writers, and each of the remaining 30 sets was written by one person. Writers wrote down characters in the pre-specified boxes and the database was created by scanning the data sheets by an image scanner. The size of each image is 100100 pixels with 256 gray levels. Since each pixel needs one byte of memory, the size of the entire database PE92 turned out to be about 2.3 GB. Finally we obtained a raw data profile of PE92 by calculating various statistics of its image data.

Multimedia Database Systems as the tool to extract and generate additional values from multimedia 'Contents' are discussed in this paper with putting emphasis on the mediator functions between users and contents. Firstly, we discuss about 'what to do' from the view point of four promising contents sources: 'on the network,' 'in the digital broadcasting' 'in the library' and 'in the real world.' From this view pont, four types of multimedia database systems are defined. 'What to do' for each database system is also discussed. Two concrete multimedia database systems with unique mediator functions, stream-type multimedia database platform GOLS and the intelligent access and authoring system using multiple media synchronization are proposed with experimental evaluation results and concrete multimedia database applications.

When people watch such motion pictures as documentaries or educational-type films, it is very natural for them to be interested in moving objects in the movies and be eager to know the detailed information related to these object. Therefore, a mechanism that enables users to directly pick up object information from motion pictures is necessary to make a movie system feasible. For this reason, we are researching techniques on using objects in motion pictures as hypermedia anchors. We call a movie system that provides the above mechanism a video hypermedia system. An object in a motion picture can generally be considered as a complex object which includes many parts. To allow users to obtain information related to each part, a system must be able to provide anchors corresponding to each part in each complex object. For this, authors cannot help defining all anchors in all frames, since the visual status of each part varies from moment to moment. This paper presents our approach for managing objects in motion pictures for video hypermedia systems. The main feature of the proposed method is to apply computer graphic techniques to the defining of anchors for a complex object.

In this paper, a new algorithm for selection of candidates for handwritten character recognition is presented. Since we adopt the concept of the marginal radius to examine the confidence of candidates, the evaluation function is required to describe the pattern distribution correctly. For this reason, we propose Simplified Mahalanobis distance and observe its behavior by simulation. In the proposed algorithm, first, for each character, two types of feature regions (multi-dimensional one and one-dimensional one) are estimated from training samples statistically. Then, by referring to the feature regions, candidates are selected and verified. Using two types of feature regions is a principal characteristic of our method. If parameters are estimated accurately, the multi-dimensional feature region is extremely effective for character recognition. But generally, estimation errors in parameters occur, especially with a small number of sample patterns. Although the recognition ability of one-dimensional feature region is not so high, it can express the distribution comparatively precisely in one-dimensional space. By combining these feature regions, they will work concurrently to overcome the defects of each other. The effectiveness of the method is shown with the results of experiments.

Recently, a number of concurrency control algorithms have been proposed for multidatabase system (MDBS) concurrency control methods (CCMs) and the most challenging issue of them has been a concern about how to ensure global serializability (GSR). In this paper, we examine two concurrency control algorithms of MDBS through simulation approach: optimistic ticket method (OTM) and global ticket method (GTM). In historical note, OTM is known to be the first practical solution, since this approach ensures GSR by way of automatically resolving indirect conflicts among global transactions without making any restrictions on local CCMs. However, OTM is expected to yield poor performance since it enforces all global transactions to take a local ticket which causes direct conflicts between them. In GTM, the global transaction manager in an MDBS assigns a global ticket to global transactions rather than accessing a local ticket as in OTM. Our experimental results showed that GTM outperforms OTM in cases that short timeout values are given. However, in case that the timeout value relatively becomes long, our results demonstrated that OTM outperforms GTM.

A detabase system that provides step-by-step guidance for LSI failure analysts has been developed. This system has three main functions: database, navigator, and chip tracking. The datebase stores failure analysis information such as analysis method and failure mechanisms including image data. It also stores conditions and results of each analysis step and decisions to proceeds to the next analysis step. With 2000 failure analysis cases, data retrieval takes 6.6 seconds, a table containing 20 photos is presented in 6.5 seconds, and a different set of data can be displayed in 0.6 seconds. The navigator displays a standard analysis procedure illustrated in flow charts.The chip tracking shows where the particular chip is and what analysis it is undergoing, which is useful for the situation where many chips are simultaneously analyzed. Thus, this system has good enough functions of analysis procedure management and performance of quick data access to make failure analysis easier and more successful.

This paper proposes a new method to design an optimal pipelined instructions set processor for ASIP development using a formal HW/SW codesign methodology. First, a HW/SW partioning algorithm for selecting an optimal pipelined architecture is outlined. Then, an adaptive detabase approach is presented that enables to enhance the optimality of the design through very accurate estimation of the performance of a pipelined ASIP in the HW/SW partitioning process. The experimental results show that the proposed method is effective and efficient.

For a complex object model, a form of range restriction, called specialization constraint (SC), has been studied. On the other hand, very few models have been proposed that support selective inheritance. In this paper, the following consideration is taken into SCs for a complex object medel suppoorting selective inheritance. A polynomial-time algorithm is given for deciding if a given database schema is well-formed. A sound and complete axiomatization for SCs is presented. A polynomial-time algorithm is given that decides if an SC is a logical consequence of a set of SCs. Finally, another polynomial-time algorithm is given, which decides if there exists a database that contains a given path from a given class.

As Object-Oriented Database Systems (OODBS) play an increasingly important role in advanced database systems, OODBS performance becomes a significant issue. It is well known that there is a strong relationship between performance and the concurrency control algorithms employed by the Database Management System (DBMS). Class Granularity Locking (CGL) and Class Hierarchy Granularity Locking (CHGL) are proposed as the concurrency control algorithms for OODBS to minimize the locking overhead. However, their basic characteristics, including the licking overhead and concurrency, have not been extensively investigated and it is not known which one is most appropriate for the general case. In this paper, we construct a simulation model for OODBS and carry out several performance evaluation studies on these two Class-Hierarchy Locking protocols and the Non Class-Hierarchy Locking (NCL) protocol. The NCL protocal is a variation of the conventional two phase locking protocol being applied to OODBS data structures.

This paper discusses an object-oriented approach to temporal multimedia data modeling in OMEGA; a multimedia database management under development at the University of Library and Information Science. An object-orientated approach is necessary to integrate various types of heterogeneous multimedia data, but it has become clear that current object-oriented data models are not sufficient to represent multimedia data, particularly when they are temporal. For instance, the current object-oriented data models cannot describe objects whose attribute values change time-dependently. Also, they cannot represent temporal relationships among temporal multimedia objects. We characterize temporal objects as instances of a subclass of class TimeInterval with the temporal attributes and the temporal relationships. This temporal multimedia data model is designed upward compatible with the ODMG-93 standard object model. To organize a temporal multimedia database, a five temporal axes model for representing temporal multimedia objects is also introduced. The five temporal axes--an absolute, an internal, a quasi-, a physical, and a presentation time axis--are necessary to describe time-dependent properties of multimedia objects in modeling, implementing and use. A concrete example of this organization method is also illustrated.

Scientific database systems for the analysis of genes and proteins are becoming very important these days. We have developed a deductive database system PACADE for analyzing the three dimensional and secondary structures of proteins. In this paper, we describe the statistical data classification component of PACADE. We implemented the component for cluster analysis and discrimination analysis. In addition, we enhanced the aggregation function in order to calculate the characteristic values which are useful for data classification. By using the cluster analysis function, the proteins are thereby classified into different types of structural characteristics. The results of these structural analysis experiments are also described in this paper.

This papaer presents a data model and the database system architecture to handle multimedia data, especially video (or image sequence) data. A new scheme AIS diagram" is introduced, by which all informations about entities and relationships among bitmap frames or textual informations are described in a uniform way. We focus on the integration of engineering data. The most important problem to be solved is how to capture the objects" in each frame and to represent them in the data model. For this purpose we propose physical cut" and logical cut" as a unit of information in image sequences and, using those concepts, we developed a prototype system for multimedia data processing on a conventional database system.

Flora is a functional-style language for object and relational algebra. It has been designed for efficient support of advanced database languages combining rules and objects using compilation and optimization. Flora is a strongly typed language based on an OO data model and incorporating support for collection-oriented computational capabilities. In this paper, we describe the design and architecture of the Flora optimizer which is rule-based, yet doing cost-based optimization. The optimizer uniformly captures logical, semantic and implementation knowledge regarding the execution system and the applications by means of assertions. This framework eases extensibility and enables efficient query rewriting.

As the Hypertext Transfer Protocol (HTTP) becomes more popular for network communication, network loads in areas with less developed network infrastructures will be an increasing problem. This paper presents a system which extends a WWW-server with a gateway to an RDBMS and a mail program, allowing for interactive query formulation together with return of potentially large query results by e-mail. These results can then be downloaded by the user when network loads are low.

This paper describes the architecture and storage structure of a new interactive multimedia information system called VideoReality. VideoReality is based on a visual conducting model, which describes the information retrieval process that occurs when people observe visible objects in the real world. VideoReality provides a spatial and temporal spread of a virtual video space from a set of stored video streams. The video space has a three-layered structure similar to that of the ANSI/X3/SPARC three-schema architecture. Users can move their eyes and watch objects freely in the video space, just as if they were viewing the real world. This paper also presents a prototype application system called Electronic Aquarium'