• KIISE Transactions on Computing Practices
• /
• v.21 no.8
• /
• pp.513-523
• /
• 2015

A complex event processing system, becoming useful in real life domains, efficiently processes stream of continuous events like sensor data from IoT systems. However, those systems do not work well on some types of queries yet, so that programmers should be careful about that. For instance, they do not sufficiently provide detailed guide to choose efficient queries among the almost same meaning queries. In this paper, we propose an query preprocessing tool for event stream processing systems, which helps programmers by giving them the hints to improve performance whenever their queries fall in any possible bad formats in the performance sense. We expect that our proposed module would be a big help to increases productivity of writing programs where debugging, testing, and performance tuning are not straightforward.

• The Transactions of the Korea Information Processing Society
• /
• v.2 no.1
• /
• pp.1-11
• /
• 1995

Object-oriented database systems represent the complex data model of real- world and manage the complex data. An object manager handles the manipulation and access of all objects in object-oriented database management systems. In this paper, we not only propose the design rules of an object manager interface(OMI) which is specified the calling function and the semantics of an object manager for object-oriented query processing, but also implement the OMI based on the rules. The OMI implemented supports the independently developing environment of query processing and object management modules, and can be applicable to various applications, and also provides the efficient access method to users.

• Proceedings of the KSRS Conference
• /
• 2002.10a
• /
• pp.138-143
• /
• 2002

This paper describes a framework for extending GIS databases to support moving object data type and query language. The rapid progress of wireless communications, positioning systems, and mobile computing devices have led location-aware applications to be essential components for commercial and industrial systems. Location-aware applications require GIS databases system to represent moving objects and to support querying on the motion properties of objects. For example, fleet management applications may require storage of information about moving vehicles. Also, advanced CRM(Customer Relationship Management) applications may require to store and query the trajectories of mobile phone users. In this trend, maintaining consistent information about the location of continuously moving objects and processing motion-specific queries is challenging problem. We formally define a data model and query language for mobile objects that includes complex evolving spatial structure, and propose core algebra to process the moving object query language. Main profit of proposed moving objects query language and algebra is that proposed model can be constructed on the top of GIS databases.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.7
• /
• pp.3041-3063
• /
• 2018

Community search aims at finding a meaningful community that contains the query node and also maximizes (minimizes) a goodness metric. This problem has recently drawn intense research interest. However, most metric-based algorithms tend to include irrelevant subgraphs in the identified community. Apart from the user-defined metric algorithm, how can we search the natural community that the query node belongs to? In this paper, we propose a novel community search algorithm based on the concept of the k-hop and local distance dynamics model, which can naturally capture a community that contains the query node. The basic idea is to envision the nodes that k-hop away from the query node as an adaptive local dynamical system, where each node only interacts with its local topological structure. Relying on a proposed local distance dynamics model, the distances among nodes change over time, where the nodes sharing the same community with the query node tend to gradually move together, while other nodes stay far away from each other. Such interplay eventually leads to a steady distribution of distances, and a meaningful community is naturally found. Extensive experiments show that our community search algorithm has good performance relative to several state-of-the-art algorithms.

• Journal of Korea Multimedia Society
• /
• v.14 no.2
• /
• pp.269-281
• /
• 2011

For the MD-TIX(multidimensional type inheritance index) that supports query processing for the type inheritance concept in XML databases, this paper presents an index tuning algorithm that enhances the performance of the XML query processing according to the query pattern. The MD-TIX uses a multidimensional index structure to support complex XML queries involving both nested elements and type inheritance hierarchies. In this index tuning algorithm, we first determine a shape of index page regions by using the query information about the user's query pattern, and then construct an optimal MD-TIX by applying a region splitting strategy that makes the shape of the page regions into the predetermined one. The performance evaluation results indicate that the proposed tuning algorithm builds an optimal MD-TIX by a given query pattern, and in the case of the three-dimensional query regions for the nested predicates of path length 2, the performance is much enhanced according to the skewed degree of the query region's shape.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.38 no.5
• /
• pp.1-15
• /
• 2001

Expressing complex query conditions in a concise and intuitive way has been a challenge in the design of visual object-oriented query languages. We propose a visual query language called VOQL (Visual Object oriented Query Language) for object oriented databases. By employing the visual notation of graph and Venn diagram, the database schema and the advanced features of object oriented queries such as multi-valued path expressions and quantifiers can be represented in a simple way. VOQL has such good features as simple and intuitive syntax, well-defined semantics, and excellent expressive power of object-oriented queries compared with previous visual object-oriented query languages.

• Journal of KIISE:Databases
• /
• v.32 no.2
• /
• pp.177-192
• /
• 2005

In this paper, we introduce a structural redundancy method. It reduces the query processing cost incurred when reconfiguring an XML document from divided XML data in shredding XML documents into relations. The fundamental idea is that query performance can be enhanced by analyzing query patterns and replicating data essential for the query performance. For the practical and effective structural redundancy, we analyzed three types of ID, VALUE, and SUBTREE replication. In addition, if given XML data and queries are very large and complex, it can be very difficult to search optimal redundancy set. Therefore, a heuristic search method is introduced in this paper. Finally, XML query processing cost arising by employing the structural redundancy, and the efficiency of proposed search method arc analyzed experimentally It is manifest that XML read query is performed more quick]y but XML update query is performed more slowly due to the additional update consistency cost for replicas. However, experimental results showed that in-place ID replication is useful even in having excessive update cost. It was also observed that multiple-place SUBTREE replication can enhance read query performance remarkably if only update cost is not excessive.

• The KIPS Transactions:PartB
• /
• v.12B no.2 s.98
• /
• pp.191-202
• /
• 2005

The Semantic Web Services is a next-generation Web technology that supports Web services, based on the semantic Web technologies. Until now, the researches on semantic Web services may be foiled on the semantic Web document management and the inference engine to efficiently process the semantic Queries. However, in order to realize the principle semantic Web environment it is necessary to provide a semantic query interface though which users and/or agents can efficiently request semantic information. In this regard, we propose the Semantic Query Adapter(SQA) to provide a high query transparency with users, especially when querying about a complex semantic information. We first design the procedural user query interface based on a graphic view, by analyzing DAML-S Profile documents. And then, we builds a module which a user input query transforms its corresponding RDQL. We also propose the multiple semantic query generating procedure as a new method to solve the disjunctive query problem of the RDQL primitive.

• Spatial Information Research
• /
• v.3 no.2
• /
• pp.191-204
• /
• 1995

The data model is a system model which abstracts the spatial and nonspatial fea¬tures of the real world. A system defines through its data model a framework for the inner rep¬resentation of and connections with the outside world. The spatial query language is one of the most efficent framework for defining connection with outside world in the GIS. Existing GIS uses a spatial data model based on relational data model. Therefore, it has some difficulties in data abstraction and representing complex objects through inheritance. In this paper, we pro-pose an object oriented data model-Topological Object Model(TOM). TOM combines object model in ODMG and the planer topological object. Based on this model, we present an object-oriented spatial query language-OQL/Geo. OQL/Geo extends OQL in ODMG and represents TOM effectively. It also provides several operators such as geometric, topological and visible ope-rators. Moreover, it represents with diverse flexivility the request for complex spatial analysis and presentation of query results.

• The Journal of Korean Association of Computer Education
• /
• v.17 no.6
• /
• pp.103-113
• /
• 2014

This study designed and implemented a query model for consecutive analyses of dynamic multivariate graph data. First, the query model consists of two procedures; setting the discriminant function, and determining an alteration method. Second, the query model was implemented as a query system that consists of a query panel, a graph visualization panel, and a property panel. A Node-Link Diagram and the Force-Directed Graph Drawing algorithm were used for the visualization of the graph. The results of the queries are visually presented through the graph visualization panel. Finally, this study used the data of worldwide import & export data of small arms to verify our model. The significance of this research is in the fact that, through the model which is able to conduct consecutive analyses on dynamic graph data, it helps overcome the limitations of previous models which can only perform discrete analysis on dynamic data. This research is expected to contribute to future studies such as online decision making and complex network analysis, that use dynamic graph models.