• Journal of Korea Multimedia Society
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• v.23 no.7
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• pp.850-861
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• 2020

Hangul is a language that is composed of initial, medial, and final syllables. It has 11,172 characters. For this reason, the current method of designing all the characters by hand is very expensive and time-consuming. In order to solve the problem, this paper proposes an automatic Hangul font generation system and evaluates the standards for mapping Hangul characters to produce an effective automated Hangul font generation system. The system was implemented using character generation engine based on deep learning CycleGAN. In order to evaluate the criteria when mapping characters in pairs, each criterion was designed based on Hangul structure and character shape, and the quality of the generated characters was evaluated. As a result of the evaluation, the standards designed based on the Hangul structure did not affect the quality of the automated Hangul font generation system. On the other hand, when tried with similar characters, the standards made based on the shape of Hangul characters produced better quality characters than when tried with less similar characters. As a result, it is better to generate automated Hangul font by designing a learning method based on mapping characters in pairs that have similar character shapes.

• The Journal of Korea Robotics Society
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• v.19 no.2
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• pp.188-195
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• 2024

This paper proposes a photorealistic real-time dense 3D mapping system that utilizes a neural network-based image enhancement method and mesh-based map representation. Due to the characteristics of the underwater environment, where problems such as hazing and low contrast occur, it is hard to apply conventional simultaneous localization and mapping (SLAM) methods. At the same time, the behavior of Autonomous Underwater Vehicle (AUV) is computationally constrained. In this paper, we utilize a neural network-based image enhancement method to improve pose estimation and mapping quality and apply a sliding window-based mesh expansion method to enable lightweight, fast, and photorealistic mapping. To validate our results, we utilize real-world and indoor synthetic datasets. We performed qualitative validation with the real-world dataset and quantitative validation by modeling images from the indoor synthetic dataset as underwater scenes.

• Journal of the Korea Society of Computer and Information
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• v.15 no.8
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• pp.23-30
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• 2010

Flash memory is non-volatile and can retain data even after system is powered off. Besides, it has many other features such as fast access speed, low power consumption, attractive shock resistance, small size, and light-weight. As its price decreases and capacity increases, the flash memory is expected to be widely used in consumer electronics, embedded systems, and mobile devices. Flash storage systems generally adopt a software layer, called FTL. In this research, we proposed a new FTL mechanism for overcoming the major drawback of conventional block mapping algorithm. In addition to the block mapping table, a index block mapping table with a small size is used to indicate sector location. The proposed indexed block mapping algorithm by adding a small size. By the simulation result, the proposed FTL provides an enhanced speed than a conventional hybrid mapping algorithm by around 45% in average, and the requirement of mapping memory is also reduced by around 12%.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.1
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• pp.19-30
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• 2014

For the expansion of the Semantic Web, studies in converting the data stored in the relational database into the ontology are actively in process. Such studies mainly use an RDB to RDF mapping model, the model to map relational database components to RDF components. However, pre-proposed mapping models have got different expression modes and these damage the accessibility and reusability of the users. As a consequence, the necessity of the standardized mapping language was raised and the W3C suggested the R2RML as the standard mapping language for the RDB to RDF model. The R2RML has a characteristic that converts only the relational database schema data to RDF. For the same reasons above, the ontology about the relation data between table name and column name of the relational database cannot be added. In this paper, we propose an RDB to RDF mapping system considering semantic relations of RDB components in order to solve the above issue. The proposed system generates the mapping data by adding the RDFS attribute data into the schema data defined by the R2RML in the relational database. This mapping data converts the data stored in the relational database into RDF which includes the RDFS attribute data. In this paper, we implement the proposed system as a Java-based prototype, perform the experiment which converts the data stored in the relational database into RDF for the comparison evaluation purpose and compare the results against D2RQ, RDBToOnto and Morph. The proposed system expresses semantic relations which has richer converted ontology than any other studies and shows the best performance in data conversion time.

• Korean Journal of Computational Design and Engineering
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• v.9 no.3
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• pp.192-202
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• 2004

This paper introduces an approach to semantic mapping using Product ontology for CPC environment. In CPC environment, it is necessary that the participants in a product life cycle should share the same understanding about the semantic of product terms. For example, they should know that although 'COMPONENT' and 'ITEM' are different word-expressions, they could have the same meaning. In order to handle such terms in the information system, it is desirable that the system automatically recognizes that the terms have the same semantics. Serving this purpose, we described an ontology design methodology using first order logic, knowledge interchange format, and knowledge engineering process. In our approach, we investigated domain knowledge of the Bill Of Material, and then designed Product ontology of it. Based on the ontology, we described syntactic translation, semantic translation, and semantic mapping procedure with an example.

• Korean Journal of Computational Design and Engineering
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• v.9 no.3
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• pp.226-237
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• 2004

If the topology changes in the re-generation step of the history-based and feature-based CAD systems, it is difficult to identify an entity in the old model and find the same entity in the new model. This problem is known as 'persistent naming problem'. To exchange parametric CAD models, the persistent naming problem and the naming mapping problem must be solved among different CAD system, which use different naming scheme. For CAD model exchange the persistent naming has its own characteristics compare to that for CAD system development. This paper analyses previous researches and proposes a solution to the persistent naming problem for CAD model exchanges and to the naming mapping problem among different naming schemes.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2002.05a
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• pp.115-122
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• 2002

O-R 매핑툴을 이용하면 업체별로 상이하며 가변적인 요소를 포함하는 전자 상거래 시스템을 효과적으로 구현할 수 있다. 본 논문에서는 전자상거래 시스템을 위한 범용적 O-R Mapping Tool인 Object $Organizer{\;}^{TM}$를 소개하고, 이를 설계하고 구현하기 위해 이용된 접근법에 대해 설명한다. 기존의 0-R 매핑툴에 대한 분석을 통해 사용 편의성과 수행 성능을 개선할 수 있도록 설계하였으며 전자 상거래 시스템의 구현 방법에서 일반화될 수 있는 부분을 추출하기 위하여 개발 프로세스와 구현 방식을 분석하였다. 또한 전자 상거래 시스템의 요구 사항을 충분히 반영할 수 있는 애플리케이션도메인을 선정하여 현업의 구체적인 요구 사항을 효과적으로 처리 가능하도록 설계하였다. 본 논문은 전자 상거래 시스템에 범용적으로 사용될 수 있는 O-R 매핑툴의 구현 방향을 제시했으며 Object $Organizer{\;}^{TM}$를 통해 이를 구현하였다. O-R 매핑툴의 범용성을 확보하기 위해 기존의 제품을 분석하고 전자상거래 시스템의 구현 방법을 분석하고 일반화하였으며 실제 전자 상거래 애플리케이션을 구현해 봄으로써 Object $Organizer{\;}^{TM}$의 개발 효율성을 평가하였다.

• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.104-104
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• 2002

목적： SAAV sequence를 이용하여 동시에 획득한 동맥과 정맥의 두 MRA 영상을 Color Mapping으로 동맥과 정맥을 구분하여 한 영상에 나타냄으로써 AVM 이나 DAVF 등과 같은 혈관질환의 임상적 진단 및 치료에 도움을 주고자 하였다. 대상 및 방법： 일반적으로 MRA 영상은 사전 포화방법(presaturation)을 이용한 2D TOF 기법을 통하여 동맥과 정맥을 구분하여 영상을 획득한다. 이러한 일반적인 사전포화방법을 응용한 SAAV 기법은 일정영역을 미리 포화(saturation)시킨 후 포화영역의 위, 아래의 영역을 한번에 영상화하여 동맥과 정맥의 구분된 영상을 한번에 획득할 수 있다. 마산 삼성병원의 0.3T MRI system(Megfinder, AILab. Korea)에서 SAAV sequence를 이용하여 정상적인 피험자로부터 목 부위의 동맥과 정맥 혈관영상을 동시에 얻었다. 이들의 각 2D 영상을 Color Mapping으로 조합한 후 Maximum Intensity Projection(MIP) 기법을 통해 3D Artery-Vein Color Mapping(AVCM) MRA 영상으로 재구성하였다. 3명의 피험자에 대한 SAAV MRA data를 256$\times$256$\times$64(resolution： 0.89$\times$0.89$\times$2㎣)로 획득하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.2
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• pp.105-110
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• 2002

For the accuracy assessment of DTM obtained by Airborne Laser Mapping Systems (ALMS), we selected 500 m spaced test points and analyze the accuracy of the DTM by various methods including GPS survey. To estimate the height at the point in between the test points of the DTM we produced a TIN, and to analyze the accuracy we use a GPS coverage map overlaid with the TIN. Compared with the existing method, DTM by ALMS is shown to be relatively accurate, and therefore, ALMS is applicable to 1/5000 digital terrain mapping.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.295-303
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• 2005

Semantic Web and its related technologies have been opening the era of information sharing via Web. In the meantime, there are several huddles to overcome toward the new era and one of the major huddles is information integration issue unless we build and use a single unified but huge ontology which address everything in the world. Particularly in e-business area, information integration problem must be a great concern in search and comparison of products from various internet shopping sites and e-marketplaces. To overcome such an information integration problem, we propose an ontology driven mapping algorithm between heterogeneous product classification and description frameworks. We also perform comparative evaluation of the proposed mapping algorithm against a well-known ontology mapping tool, PROMPT.