• Journal of Information Processing Systems
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• v.8 no.4
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• pp.653-668
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• 2012

In this study, an improved HMM based recognition model is proposed for online English and Korean handwritten characters. The pattern elements of the handwriting model are sub character strokes and ligatures. To deal with the problem of handwriting style variations, a modified Hierarchical Clustering approach is introduced to partition different writing styles into several classes. For each of the English letters and each primitive grapheme in Korean characters, one HMM that models the temporal and spatial variability of the handwriting is constructed based on each class. Then the HMMs of Korean graphemes are concatenated to form the Korean character models. The recognition of handwritten characters is implemented by a modified level building algorithm, which incorporates the Korean character combination rules within the efficient network search procedure. Due to the limitation of the HMM based method, a post-processing procedure that takes the global and structural features into account is proposed. Experiments showed that the proposed recognition system achieved a high writer independent recognition rate on unconstrained samples of both English and Korean characters. The comparison with other schemes of HMM-based recognition was also performed to evaluate the system.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.788-791
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• 2008

On this study, following works have been carried out : division of Han River Basin into 24 sub basins, use of rainfall data of 151 stations to make spatial distribution of rainfall, selection of control points such as Soyanggang Dam, Chungju Dam, Chungju Release Control Dam, Heongseong Dam, Hwachun Dam, Chuncheon Dam, Uiam Dam, Cheongpyung Dam and Paldang Dam, selection of SSARR (Streamflow Synthesis and Reservoir Regulation) model as a hydrologic model, preparation of input data of SSARR model, sensitivity analysis of parameter using hydrologic data of 2002. The sensitivity analysis showed that soil moisture index versus runoff percent (SMI-ROP), baseflow infiltration index versus baseflow percent (BII-BFP) and surface-subsurface separation (S-SS) parameters are higher sensitive parameters to the simulation result.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.136-139
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• 2004

This thesis is realization of embedded system that of MPEG-2 down conversion using IDCT. A method for down conversion of MPEG compressed video is to perform low-pass filtering and sub-sampling after full decompression. However, this method is need large memory and high computational complexity. Recent research has been focussed on the down conversion in the DCT domain. But DCT method is reduced image qualify. The embedded system is require low complexity, and high speed algorithm. When applied to embedded system that down conversion method, DCT method is played average 29 frame per second, and better 25% than spatial-domain down conversion.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.3
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• pp.181-193
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• 2010

The paper presents an alternative way to classical stereocorrelation. First, 2D image processing of random patterns is described. Sub-pixel displacements are determined using phase analysis. Then distortion evaluation is presented. The distortion is identified without any assumption on the lens model because of the use of a grid technique approach. Last, shape measurement and shape variation is caught by fringe projection. Analysis is based on two pin-hole assumptions for the video-projector and the camera. Then, fringe projection is coupled to in-plane displacement to give rise to 3D measurement set-up. Metrological characterization shows a resolution comparable to classical (stereo) correlation technique ($1/100^{th}$ pixel). Spatial resolution seems to be an advantage of the method, because of the use of temporal phase stepping (shape measurement, 1 pixel) and windowed Fourier transform (in plane displacements measurement, 9 pixels). Two examples are given. First one is the study of skin properties; second one is a study on leather fabric. In both cases, results are convincing, and have been exploited to give mechanical interpretation.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.93-96
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• 2001

공간 데이터베이스에서는 공간 객체에 대해 객체마다 서로 다른 보안 등급을 설정함으로써 공간 객체에 대한 보안을 유지하고 있다. 다단계 보안을 사용하여 사용자의 보안 등급에 따라 공간 객체에 대한 접근을 제어할 경우 인접 객체와의 위상관계를 통해서 공간 정보뿐만 아니라 비공간 정보의 노출(information flow)이라는 문제가 발생하게 된다. 이에 대한 해결책으로 데이터베이스에 대한 부분집합만을 추출하여 사용자의 권한에 맞는 질의 결과를 제공하는 것이다. 즉 공간 뷰를 정의함으로써 사용자 등급에 맞는 결과 집합(result set)을 제공함으로써 보다 효율적인 연산을 수행할 수 있게 된다. 따라서 본 논문에서는 실세계의 지리 객체들에 대한 다양한 사용자 관점과 다단계 보안 등급을 가진 뷰를 지원하기 위해 관계형 데이터베이스의 뷰 개념을 확장한 공간 데이터베이스의 공간 뷰를 제안하고, 공간 연산 시 발생하는 정보 흐름 제어를 위한 방법을 제시한다.

• Korean Journal of Remote Sensing
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• v.11 no.1
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• pp.1-17
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• 1995

Using remotely sensed data(MOS-1) and other spatial data such as aerial photos and topographic maps, 10 kind of thematic layers were prepared with Arc/Info system for watershed management of Nam Khane River, northern part of Laos. The characteristics of landuse distribution of some criteria which like village, sub-basin, elevation and slope were clarified by overlaying each layer. Therefore, statistic data including shifting cultivation area were produced from database layer. Through the manipulation of some data of each layer, suitable area for permanent paddy cropping converted from the fallow and shifting cultivation area was extracted.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2162-2173
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• 2021

In this paper, the coupling of fine-mesh computational fluid dynamics (CFD) thermal-hydraulics (TH) code and neutronics code is achieved using the Ansys Fluent User Defined Function (UDF) for code development, including parallel meshing mapping, data computation, and data transfer. Also, some CFD schemes are designed for mesh mapping and data transfer to guarantee physical conservation in the coupling computation. Because there is no rigorous research that gives robust guidance on the various CFD schemes that must be obtained before the fine-mesh coupling computation, this work presents a quantitative analysis of the CFD meshing and mapping schemes to improve the accuracy of the value and location of key physical prediction. Furthermore, the effect of the sub-pin scale coupling computation is also studied. It is observed that even the pin-resolved coupling computation can also create a large deviation in the maximum value and spatial locations, which also proves the significance of the research on mesh mapping and data transfer for CFD code in a coupling computation.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.3
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• pp.144-152
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• 2021

Sanankerto is one of pilot projects for tourism villages in Indonesia due to its natural tourism potential with a 24-ha bamboo forest located in Boon Pring Andeman area. However, the distribution of existing bamboo has never been identified or mapped. Thus, the mana gement is facing difficulty in planning and developing tourism potential as well as spatial management in the area. Therefore, the objectives of this study were to identify and analyze the structure of bamboo vegetation in the Boon Pring Tourism village an d to perform vegetation mapping. The type of research was descriptive exploratory with a cluster sampling technique (i.e., a two-stage cluster) covering an area of ± 10 ha. Bamboo vegetation analysis was performed by calculating diversity index (H'), evenness index (E), and Species Richness index (R). Data were collected through observation and interviews with local people and the manager to determine zonation division. Mapping of bamboo vegetation based on zoning was processed into thematic maps using ArcG is 10.3. Micro climatic factors were measured with three replications for each sub -cluster. Data were analyzed descriptively and quantitatively. Nine species of bamboo identified. Diversity, evenness, and species richness indices differed at each location. Activities of local communities, tourists, and manager determined the presence, number, and distribution of bamboo species. These bamboo distribution maps in three zoning (utilization, buffer, and core) can be used by manager for planning and developing natural tourism potential.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.176-176
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• 2023

The Tonle Sap is the richest and diverseness of freshwater ecosystem in Southeast Asia, receiving nurturing water flows from the Mekong and its immediate basin. In addition, the rapid development in the Tonle Sap Lake (TSL) Basin, and flood inundation may threaten the natural diversities and characteristics. The impacts of flood inundation in 11 sub-basins contributing to the Tonle Sap Lake were assessed using the Rainfall-Runoff-Inundation (RRI) model to quantify the potential magnitude and extent of the flooding. The RRI model is set up by using gauged rainfall data to simulate the information of river discharge and flood inundation of huge possible flood events. Moreover, two satellite precipitation products (SPPs), CHIRPS and GSMaP, within respectively spatial resolutions of 0.05° and 0.1°, are utilized as an input for the RRI model to simulate river discharge, flood depth, and flood extent for the great TSL Basin of Cambodia. This study used statistical indicators such as NSE, PBIAS, RSR, and R2 as crucial indices to evaluate the performance of the RRI model. Therefore, the findings of this study could provide promising guidance in hydrological modeling and the significant implications for flood risk management and disaster preparedness in the region.

• Current Optics and Photonics
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• v.7 no.2
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• pp.183-190
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• 2023

Three-dimensional (3D) displays provide a significant advantage over traditional 2D displays by offering realistic images, and table-style displays in particular are ideal for generating 3D images that appear to float above a table. These systems are based on multiview displays, and are typically operated using temporal or spatial multiplexing methods to expand the viewing zone (VZ). The VZ is an expanded space that results from merging the sub-viewing zones (SVZs) from which an individual view is made. To increase the viewing angle, many SVZs are usually required. In this paper, we propose a table-ornament electronic holographic display that utilizes 3f parabolic mirrors. In holography, the VZ is not simply expanded but synthesized from SVZs to implement continuous motion parallax. Our proposed system is small enough to be applied as a table ornament, in contrast to traditional tabletop displays that are large and not easily portable. By combining multiview and holographic technologies, our system achieves continuous motion parallax. Specifically, our system projects 340 views using a time-multiplexing method over a range of 240 degrees.