• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1294-1306
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• 1996

To achieve high compression ratio for Hangul texts, in this paper two text compression algorithms which use the structural feature of Hangul, the frequency of postpositional words, are proposed. The performances of these proposed algorithms are also compared with previous text compression algorithms. The proposed compression algorithms named HLZ77 and HLZW come out from the modification of previous algorithms LZ77 and :ZW, respectively. The major distinction of the proposed ones is that the proposed algorithms use the fixed dictionary of selected postpositional words that appear most frequently in Hangul texts. The performances of HLZ77 and HLZW also are compared with those of LZ77 and LZW, respectively, with respect to the compression ratio. According to the result of performance study, the proposed algorithms are better than the previous algorithms for descriptive Hangul text snce the structural feature of Hangul is helpful to achievement of high compression ratio.

• Journal of the Korean Society of Radiology
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• v.10 no.8
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• pp.571-576
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• 2016

3D printing has recently been used in various fields. Among various applications, 3D face data must be generated for 3D face printing. A laser scanner is used to acquire 3D face data, but there is a restriction that a person should not move during scanning. In this paper, we propose a 3D face modeling method based on a single image and a face transformation system to use the generated 3D face for virtual cosmetic surgery. We have defined facial feature points from the 3D face database for 3D face data generation. After extracting feature points from a single face image, 3D face of the input face image is generated corresponding to the 3D face feature points defined from the 3D face database. After 3D face modeling, 3D face modification part is applied for use such as virtual cosmetic surgery.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.1078-1099
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• 2021

Traditional image steganography hides secret information by embedding, which inevitably leaves modification traces and is easy to be detected by steganography analysis tools. Since coverless steganography can effectively resist steganalysis, it has become a hotspot in information hiding research recently. Most coverless image steganography (CIS) methods are based on mapping rules, which not only exposes the vulnerability to geometric attacks, but also are less secure due to the revelation of mapping rules. To address the above issues, we introduced camouflage images for steganography instead of directly sending stego-image, which further improves the security performance and information hiding ability of steganography scheme. In particular, based on the different sub-features of stego-image and potential camouflage images, we try to find a larger similarity between them so as to achieve the reversible steganography. Specifically, based on the existing CIS mapping algorithm, we first can establish the correlation between stego-image and secret information and then transmit the camouflage images, which are obtained by reversible sub-feature retrieval algorithm. The received camouflage image can be used to reverse retrieve the stego-image in a public image database. Finally, we can use the same mapping rules to restore secret information. Extensive experimental results demonstrate the better robustness and security of the proposed approach in comparison to state-of-art CIS methods, especially in the robustness of geometric attacks.

• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.139-149
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• 2024

In this paper, we propose the standard architecture for the IFF interface SW in naval combat management system(CMS). The proposed standard interface architecture is a method designed to reduce modification efforts and man-month of reliability test for the existing the IFF interface SW of 11 types. We identified highly dependent CMS and GFE information, leading to the redefinition of standard requirements and functions, and proceeded with the initial design applying the Naval Shield Component Platform(NSCP). Subsequently, using the Feature Model, we derived additional common and variable elements for the interface of multiple CMS and GFE. Considering the S.O.L.I.D principles, we designed the final architecture. The proposed IFF Interface SW, based on the standard architecture, is expected to enhance management efficiency through a common architecture, increase code reusability and scalability, and reduce development costs by shortening reliability testing times.

• Spatial Information Research
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• v.10 no.3
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• pp.455-468
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• 2002

Toward the systematic and efficient management of national land, National Geography Institute(NGI, National mapping agency) has been producing national basemap in automated process since middle of 1980's. Under the National Geographic Information System(NGIS) Development Plan, NGI began to produce digital maps in the scales of 1:1,000, 1:5,000, 1:25,000 since 1995. However, those of digital maps that have been generated under NGIS Development Plan need to be modified and corrected due to lack of technology and experience in making digital maps. In this context, those digital maps generated are currently in great need for improving the data dictionary. It is fully appreciated in previous research that data dictionary will be a key element far users and generators of digital maps to rectify the existing problems in digital maps as well as to maximize the application of digital maps. In this paper, we analyzed existing problems in digital maps based on previous researches and interviews with engineers in different fields of geospatial engineering. And then, the existing data dictionary has been redefined and modified. In the line of modification process, a relational matrix was established fur each topographic feature defined in the existing feature classification system. This paper presents newly proposed data dictionary which conforms to newly defined feature classification system from previous research performed by NGI.

• Journal of the Korea Computer Industry Society
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• v.5 no.4
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• pp.503-510
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• 2004

The summary of this paper is as follows. The literature on existing expert system maintenance software technique are reviewed in Module program, a case of assembly line process problem at construction industry and planning expert system to solve this problem at construction as a standard configured process system are discussed. the regenerative expert system approach for the construction process expert system and its example for the assembly line construction process appear in the research also, this paper shows the architecture and some feature of the CES.(Construction Expert System), which is a prototype implemented for the regenerative expert system approach. the paper introduce the framework of the regenerative expert approach as a general framework of developing and maintaining a large-scale expert systems.

• Journal of applied mathematics & informatics
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• v.3 no.2
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• pp.217-234
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• 1996

This report introduces a faster parallel LU decomposi-tion algorithm that gives a speedup almost equal to the number of nodes used. The new algorithm takes an advantage of an important C feature that lays out a matrix using a row major scheme and is based on the currently widely used LU decomposition algorithm with one major modification to eliminate most of the communication overhead. Empirical results are included in this report. For example solving a dense matrix that contains 100,000,000 elements gives a speedup of 50 when executed on 50 nodes of an intel Paragon in parallel.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.766-769
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• 2000

In recent years, Internet/Intranet represents the next generation of computing environment. Therefore, it is necessary to integrate WWW((World Wide Web) over internet/intranet and DBMS(Database Management System) in proportion to the increase of various users' request and an amount of data variety. Also, also full variety of service over WWW need to accomplish rapidly modification of bug and make a betterment of system according to a feature of rapid change of information and an importance of interaction with users. The typical CGI method commonly used to connect with database has a disadvantage in time and resources in system due to frequent connection with database. Therefore, this paper provides the conceptual structure and implementation of information management system over WWW with applying a recent information technology called ASP(Active Server Pages) that controls and arranges client logic dynamically in server-side and introducing a concept of working group and folder to database design.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.2
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• pp.141-146
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• 2002

Stereolithography is the best known as rapid prototyping system. It uses the STL format data which is generated from CAD system. In this study, One of the main function of this developed CAM system deals with shape modification which divide a shape into two parts or more. The cross section of a STL part by a z-level is composed with nested or single polygonal closed loop. In order to make RP product, closed loops must fill with triangular facets from SSET and recover sliced triangular facets which is located normal direction to the cross sectional plane. The system is development by using Visuall C++ compiler in the environment of pentium PC. Operating system is Windows NT workstaion from Micro-Soft.

• Atmosphere
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• v.23 no.1
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• pp.33-37
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• 2013

In meteorology, exploitation of Kalman filter as a data assimilation system is virtually impossible due to simultaneous requirements of adjoint model and large computer resource. The other substitute of utilizing ensemble Kalman filter is only affordable by compensating an enormous usage of computing resource. Furthermore, the latter employs ensemble integration sets for evolving the background error covariance matrix by compensating the dynamical feature of the temporal evolution of weather conditions. We propose a new implementation method that works without the adjoint model by utilizing the explicit expression of the background error covariance matrix in backward evolution. It will also break a barrier in the evolution of the covariance matrix. The method may be applied with a slight modification to the real time assimilation or the retrospective analysis.