• The KIPS Transactions:PartD
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• v.8D no.4
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• pp.377-386
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• 2001

In spatial database system, spatial view is supported for efficient access method to spatial database and is managed by materialization and non-materialization technique. In non-materialization technique, repeated execution on the same query makes problems such as the bottle-neck effect of server-side and overloads on a network. In materialization technique, view maintenance technique is very difficult and maintenance cost is too high when the base table has been changed. In this paper, the SVMT (Spatial View Materialization Technique) is proposed by using R-tree re-construction. The SVMT is a technique which constructs a spatial index according to the distribution ratio of objects in spatial view. This ratio is computed by using a SVHR (Spatial View Height in R-tree) and SVOC (Spatial View Object Count). If the ratio is higher than the average, a spatial view is materialized and the R-tree index is re-used. In this case, the root node of this index is exchanged a node which has a MBR (Minimum Boundary Rectangle) value that can contains the whole region of spatial view at a minimum size. Otherwise, a spatial view is materialized and the R-tree is re-constructed. In this technique, the information of spatial view is managed by using a SVIT (Spatial View Information Table) and is stored on the record of this table. The proposed technique increases the speed of response time through fast query processing on a materialized view and eliminates additional costs occurred from repeatable query modification on the same query. With these advantages, it can greatly minimize the network overloads and the bottle-neck effect on the server.

• Journal of Information Processing Systems
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• v.9 no.4
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• pp.511-537
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• 2013

Numerous data intensive applications demand the efficient processing of a new type of query, which is called a progressive query (PQ). A PQ consists of a set of unpredictable but inter-related step-queries (SQ) that are specified by its user in a sequence of steps. A conventional DBMS was not designed to efficiently process such PQs. In our earlier work, we introduced a materialized view based approach for efficiently processing PQs, where the focus was on selecting promising views for materialization. The problem of how to efficiently find usable views from the materialized set in order to answer the SQs for a PQ remains open. In this paper, we present a new index technique, called the Dynamic Materialized View Index (DMVI), to rapidly discover usable views for answering a given SQ. The structure of the proposed index is a special ordered tree where the SQ domain tables are used as search keys and some bitmaps are kept at the leaf nodes for refined filtering. A two-level priority rule is adopted to order domain tables in the tree, which facilitates the efficient maintenance of the tree by taking into account the dynamic characteristics of various types of materialized views for PQs. The bitmap encoding methods and the strategies/algorithms to construct, search, and maintain the DMVI are suggested. The extensive experimental results demonstrate that our index technique is quite promising in improving the performance of the materialized view based query processing approach for PQs.

• The KIPS Transactions:PartD
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• v.16D no.3
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• pp.381-394
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• 2009

As a technique to enhance reusability for the created artifacts in software modeling process, the model driven method such like MDA has been applied. Unfortunately, the hierarchical and systematic MDA based development technique using UML is poor yet. This causes the problem that the MDA modeling with high consistency and reusability based on MDA metamodel is not being realized. To solve this problem, this paper proposes a MDA (PIM/PSM) component modeling technique using 2+1 view integrated metamodel. At first, the meta-architecture view model which can represents development process view and MVC view is defined. Then, the hierarchical integrated metamodels per view are addressed separately for modeling process and MVC at metamodel level on the hierarchy of the defined meta-architecture view model. These metamodels are defined hierarchically by layering the modeling elements in PIM and PSM pattern for UML models and GUI models. Appling the proposed metamodel to an ISMS application system, it is shown as a component modeling case study based on MDA. Through this approach, we are able to perform a component model with consistency and hierarchy corresponding to development process and MVC way. Accordingly, this may improve more independence and reusability of model.

• Journal of information and communication convergence engineering
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• v.17 no.1
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• pp.60-66
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• 2019

In this paper, we propose a new free-view three-dimensional (3D) computational reconstruction of integral imaging to improve the visual quality of reconstructed 3D images when low-resolution elemental images are used. In a conventional free-view reconstruction, the visual quality of the reconstructed 3D images is insufficient to provide 3D information to applications because of the shift and sum process. In addition, its processing speed is slow. To solve these problems, our proposed method uses a pixel rearrangement technique (PERT) with locally selective elemental images. In general, PERT can reconstruct 3D images with a high visual quality at a fast processing speed. However, PERT cannot provide a free-view reconstruction. Therefore, using our proposed method, free-view reconstructed 3D images with high visual qualities can be generated when low-resolution elemental images are used. To show the feasibility of our proposed method, we applied it to optical experiments.

• Journal of Information Technology Applications and Management
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• v.16 no.4
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• pp.245-261
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• 2009

Since XML emerged as a standard for data exchange on the web, it has been widely used for applications like e-Commerce, CRM, and BI. However, it is common that most of business data is stored in relational database systems, and it is expected that business data management would still be centered around the relational database systems. As such, the technique of viewing relational data as XML and processing XML queries against it is required. To meet such a need, in the SQL/XML standard, the functions to publish relational data as XML are provided. In this paper, we propose the techniques of providing an XML view of relational data defined by an SQL/XML statement in DTD(Document Type Definition), and of processing XPath queries against the XML view by translating them into SQL/XML statements, and describe the validation of such techniques through implementation and tests.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.757-765
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• 1996

View index techniques are proposed to process queries on views. Signature referencing techniques keep pointers with signatures of the referred object when there is any reference relationship between objects. When queries having conditions on referred object are give, disk I/Os can be reduced by checking conditions using stored signatures. Signature view index techniques proposed in this paper apply signature referencing techniques to view index by keeping not only tuple identifiers but also signatures for the tuple. When queries having conditions on views regiven, we can retrieve only tuples from a view index which satisfy given conditions by checking those with stored signatures.

• The Journal of the Korea Contents Association
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• v.14 no.4
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• pp.9-18
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• 2014

Recently, many researches have been focused on multi-view video applications and services such as wireless video surveillance networks, wireless video sensor networks and wireless mobile video. In multi-view video signal processing, to exploit the strong correlation between images acquired by different cameras plays great role in developing a core technique of multi-view video coding. This paper proposes an adaptive multi-view video interpolation technique which is applicable for multi-view distributed video coding without requiring any cooperation amongst the cameras. The proposed algorithm estimates the non-linear moving blocks and employs disparity compensated view prediction, and then fills in the unreliable blocks. Through computer simulations, it is shown that the proposed method outperforms the conventional methods.

• Transactions of Materials Processing
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• v.13 no.3
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• pp.273-278
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• 2004

This paper subscribes the measurement system that can position the target to measure by moving 2-axis stage, which is controlled by the data from image processing technique. The high resolution camera and lens are used in measurement of micro mechanical part, but the region of measurement is very small. It is necessary the re-positioning to measure several regions in one part. The system described in this paper has the accuracy with about $0.9\mu\textrm{m}$ resolution per one pixel and can be applied to measure micro mechanical part.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.1
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• pp.75-81
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• 2023

In this study, we design an optimized Graphics Processing Unit (GPU)-based GNSS signal processing technique with the goal of designing and implementing a GNSS Software Defined Receiver (SDR) that can operate in real time all-in-view mode under multi-constellation and multi-frequency signal environment. In the proposed structure the correlators of the existing GNSS SDR are processed by the GPU. We designed a memory structure and processing method that can minimize memory access bottlenecks and optimize the GPU memory resource distribution. The designed GNSS SDR can select and operate only the desired GNSS or desired satellite signals by user input. Also, parameters such as the number of quantization bits, sampling rate, and number of signal tracking arms can be selected. The computing capability of the designed GPU-based GNSS SDR was evaluated and it was confirmed that up to 2400 channels can be processed in real time. As a result, the GPU-based GNSS SDR has sufficient performance to operate in real-time all-in-view mode. In future studies, it will be used for more diverse GNSS signal processing and will be applied to multipath effect analysis using more tracking arms.

• Journal of Environmental Impact Assessment
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• v.19 no.3
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• pp.315-321
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• 2010

ArcView and water network models have been integrated to develop the water network modeling system based upon GIS. To develop this system, pre, main, and post processing systems are required. GIS programming technique was adopted by using the ArcView's script language Avenue. The input data of models have been prepared by using the AutoCAD Map3D through the conversion of modeling input data to GIS data for A city. The modeling has been implemented by using EPANET, WaterCAD, InfoWorks. To develop the post processing system, the modeling results of the water network models have been analyzed by using GIS. During the application process of the developed system to B city with 300,000 population, main problems were found in the constructed GIS DB of that city. Thus, pilot study area of B city has been constructed, and pre-, main, and post-processing techniques were invented based upon GIS. Finally, the problems related to waterworks GIS projects in Korea were discussed and solutions were suggested.