• Convergence Security Journal
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• v.15 no.2
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• pp.3-9
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• 2015

The development of the digital compression technology and the broadcasting receiver's processing power make it possible to apply a multi-view function to the broadcasting services. The multi-view function is usually utilized to provide simultaneously several programs to viewers or to implement a multi-angle service of a sports program that allows a viewer to choose a video of his/her prefer viewpoint. The paper proposes an integrated method for utilizing a multi-view function in the digital broadcasting environment in which more than 100 programs are on air and there may be various data services which want to use multi-view video clips. For the purpose, a method of composing and transmitting multi-view videos and related information has been devised and a Java API to utilize the rapid editing function of a decoding chip-set has been implemented to clip, resize, and display parts of the multi-view videos.

• The KIPS Transactions:PartD
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• v.10D no.2
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• pp.221-232
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• 2003

This paper addresses the query processing component of a wrapper system for a relational database model based on the XML view in integrating databases. The schema of a relational database is represented as XML Schema that is proposed by W3C. Users submit a query using the XML query language XQuery over the XML Schema. The wrapper system to be developed supports an user-defined XML view. XQuery is also used as the view definition language. In this environment, this paper suggests a new XML query processing model. We propose the composition algorithm of an XML view with an user query, the translation algorithm of XQuery into SQL, and the XML template construction algorithm for generating XML documents.

• Journal of KIISE:Databases
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• v.28 no.4
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• pp.620-632
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• 2001

This paper proposes a mediator system which can provide a view management function in the today's heterogeneous computing environment including operating system database management systems and other software. while most mediators use view modification mechanism only, the use of view materialization is also considered in this research. In order to optimize the management cost for materialized views the proposed method applies a decay factor for modeling the access behaviors of views In other words, the most recently access pattern gets the highest attention in the optimization process all the necessary it with the CORBA.

• Journal of Broadcast Engineering
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• v.22 no.3
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• pp.405-408
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• 2017

Based on the fact that high similarities exist between viewpoints of multi-view images, MV-HEVC achieves high encoding efficiency by performing conventional temporal direction prediction in a single viewpoint as well as inter-view prediction between viewpoints. In this paper, we propose to integrate SHVC and MVC (Multi-view Video Coding) to implement scalable multi-view video encoder using HEVC as a base layer. According to experimental results, it is verified that the BD-PSNR improvement reaches up to 1.5dB while reducing the BD-Bitrate by around 50~60%.

• Proceedings of the CALSEC Conference
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• 1997.11a
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• pp.59-68
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• 1997

CALS 통합 데이터베이스는 지역적으로 분산되어 있고 이질적인 형태를 갖는 기술 및 관리정보를 디지털 형태로 변환하여 교환 및 공유할 수 있도록 하는 정보 공유 체제로 CALS 구현의 핵심 정보 기술이다. 또한, 분산된 CALS 정보는 체계적으로 통합되어 글로벌 뷰를 제공하여야 하므로 이질의 데이터베이스를 통합하는 것이 매우 중요하다. 본 논문에서는 CALS 통합 데이터베이스의 주요 핵심 기술을 고찰하고, 이를 분산 객체 환경인 CORBA하 에서 구현하기 위한 시스템 모형을 제시한다.

• The Journal of the Korea Contents Association
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• v.13 no.6
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• pp.9-19
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• 2013

In this paper, we develop a Spatio-Temporal graph as of a key component of our knowledge representation Scheme. We design an integrated representation scheme to depict not only present and past but future in parallel with the spaces in an effective and intuitive manner. An event in general occupies not only a space but a time. Hence a crucial premise for the simulation of virtual situations is to position events in the multi-dimensional context, that is, 3-D space extended by the temporal dimension. Furthermore an event tends to have physical, social and mental aspects intertwined. As a result we need diverse information structures and functions to model entities and relations associated with events and to describe situations in different stances or perspectives of the virtual agents. These structures and functions are implemented in terms of integrated and intuitive representation schemes at different levels such as Ontology View, Instance View, ST View, Reality View. The resulting multi-dimensional comprehensive knowledge structure accommodates multi-layered virtual world developing in the time to maximize the diversity of situations in the historical context. The viability of this knowledge representation scheme is demonstrated with a typical scenario applied to a simulator implemented based on the ST Graph. The virtual stage based on the ST graph can be used to provide natural contexts for situated learning or next-generation simulation games.

• Journal of KIISE:Software and Applications
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• v.26 no.10
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• pp.1156-1166
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• 1999

의사결정 시스템은 전사적인 의사결정과 전략적 정보수집을 위해 거대한 량의 정보를 빠른 시간내에 제공할 것을 요구한다. 데이타 웨어하우스는 이러한 정보를 신속히 제공하기 위해 여러 지역 데이타베이스로부터 필요한 정보를 사전에 추출하고 가공 및 통합하여 별도의 저장공간에 저장한다. 일반적으로, 웨어하우스 내의 정보는 지역 데이타베이스에 저장된 정보에 대한 실체화된 뷰로서 간주하며 지역 데이타의 변경에 따라 일관성을 유지하도록 반영해야 한다. 본 논문에서는 일관성을 유지하기 위해 정보 공유가 가능한 데이타 웨어하우스 시스템의 구조와 비-보상 실체 뷰 관리 기법을 제안한다. 본 논문에서 제안한 데이타 웨어하우스 시스템의 구조는 지역 데이타베이스에서 추출된 정보를 관리하는 별도의 지역 정보 관리자를 두어 뷰 관리자들 간의 정보 공유가 가능하게 한다. 비-보상 실체 뷰 관리 기법은 지역 데이타 변경 사건에 따른 뷰 관리 시 다른 사건에 의해 영향을 받지 않도록 하기 때문에 기본의 사전 보상이나 나중 보상 기법과는 달리 추가적인 질의 처리를 요구하지 않는 기법이다.Abstract A decision support system(DSS) commonly requires fast access to tremendous volume of information. A data warehouse is a database storing the information that is extracted, filtered and integrated from several relevant local databases to reply upon aggregated queries. The information stored in the data warehouse can be regarded as materialized views. The materialized view has to be modified according to the change of the corresponding local databases to preserve the data consistency. In this paper, we propose a data warehousing system architecture allowing information sharing (DAWINS), and a non-compensating materialized view maintenance algorithm(NCA). DAWINS architecture allows relevant information to be shared by individual view managers with local data manager for each local database. Unlikely to the pre- or post-compensating algorithms, which are required to remove the effects of some events to other view in the process of view maintenance, NCA does not require any additional query processing, since a local data manager in DAWINS already maintains the effects of update events occurring in local systems.

• Journal of KIISE:Databases
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• v.37 no.6
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• pp.333-342
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• 2010

Building ontology is the key factor to construct semantic web. However, this is time-consuming process. Hence, there are several approaches which automatically generate the ontologies from relational databases. Current studies on the automatic generation of the ontologies from relational database are focused on generating the ontology by analyzing the database schema and stored data. These studies generate the ontology by analyzing only tables and constraints in the schema and ignore view definitions. However, view definitions are defined by a database designer considering the domain of the database. Hence, by considering view definitions, additional classes and hierarchical relationships can be generated. And these are useful in answering queries and integration of ontologies. In this paper, we formalize the generation of classes and hierarchical relationships by analyzing existing methods, and we propose the method which generates additional classes and hierarchical relationships by analyzing view definitions. Finally, we analyze the generated ontology by applying our method to synthetic data and real-world data. We show that our method generates meaningful classes and hierarchical relationships using view definitions.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.4
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• pp.369-380
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• 2003

With the proliferation of a wireless support and the advances of mobile devices, there is a growing need of making it available for a wireless network as well. Low bandwidth of a wireless network is one of the major issues that should be considered for extending a synchronous collaboration system developed for a wired network to supuort a wireless network. We propose a priority-based view synchronization scheme, exploiting the relaxed synchronization. The proposed scheme leverages the fact that mobile users need not have the exactly same view as the users in a wired network since they usually have a limited screen size and thus focus only on part of a whole document. We evaluate the performance of a simple group editor with the propose scheme using ns -2. The performance results show that the proposed scheme keeps the message transmission delay low so that mobile users can have synchronous colloboration with wired users without signification delay. The proposed scheme is designed and implemented as a framework to support various kinds of realtime groupware applications, exploiting the existing groupware framework, Habanero. As a client program, we implemented a simple group text editor.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.775-782
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• 2004

Recently, most of global enterprises have geographically distributed organization, thus have distributed information systems which have distributed database systems. So, it is difficult for these systems to provide common views for the application programs of end users. One of solutions to solve these difficulties is an MDBS(Multidatabase System) A method to effectively implement MDBS is a schema integration. This paper proposes a methodology for a schema integration through extraction of common similar subschemas Our methodology is consisted of 5 phases : affinity analysis, extraction of similar subschemas, decision of imtegration order, resolution of semantic conflict, and schema integration. To verify the usability of our methodology, a case study is implemented with an object of MDBS. At a result, our approach can effectively be applied to the extraction of common similar subschemas and schema integration.