• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.201-205
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• 1997

With the recent advance of Web and its associated technologies, information sharing on distribute computing environments has gained a great amount of attention from many researchers in many application areas, such as medicine, engineering, and business. One basic requirement of distributed medical consultation systems is that geographically dispersed, disparate participants are allowed to exchange information readily with each other. Such software also needs to be supported on a broad range of computer platforms to increase the software's accessibility. In this paper, the development of world-wide-web based medical consultation system or radiology imaging is addressed to provide the platform independence and great accessibility. The system supports sharing of 3-dimensional objects. We use VRML (Virtual Reality Modeling Language), which is the de-facto standard in 3-D modeling on the Web. 3-D objects are reconstructed from CT or MRI volume data using a VRML format, which can be viewed and manipulated easily in Web-browsers with a VRML plug-in. A Marching cubes method is used in the transformation of scanned volume data set to polygonal surfaces of VRML. A decimation algorithm is adopted to reduce the number of meshes in the resulting VRML file. 3-D volume data are often very large-sized, and hence loading the data on PC level computers requires a significant reduction of the size of the data, while minimizing the loss of the original shape information. This is also important to decrease network delays. A prototype system has been implemented (http://netopia.snu.ac.kr/-cyber/). and several sessions of experiments are carried out.

• Journal of the Society of Naval Architects of Korea
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• v.34 no.4
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• pp.139-147
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• 1997

Most of the existing applications developed undter the DOS environment exchange information with the exterior world through reading and writing files in ASCII format. A package program consisting of numerous modules has to exchange data not only between module program and the input/output files but also between module themselves, and hence information exchange via ASCII file is increasingly inefficient and less accurate as the number of modules increases. The present paper describes the design and the implementation of the interface between the module program and the database which stores all the information necessary for the execution of the application. The interface program is then applied to the existing Propeller Design and Analysis System to show that the interface functions smoothly. The development is performed on the personal computer operating under Windows 95 rather than the workstation under Unix operating system to prove that the design and analysis work can be carried out without limit in time and space.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.153-158
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• 1998

Since the mid-1990′s, researches on 3D GIS have been regarded as one of main issues both in the academic sites and commercial vendors; recently, some prototyped systems or the first versioned software systems of commercial basis are being reported and released. Unlike conventional 2D GIS, which consists in intelligent structured GIS or desktop GIS, every 3D GIS has its own distinguished features according to data structure-supporting capability, GIS-styled functionality, external database accessibility, interfacing extents with 2D GIS, 3D visualization/texture mapping ability, and so forth. In this study, technical aspects related to system development, SERI-Web3D GIS ver. 1.2, are explained. Main features in this revised 3D GIS can be summarized: 2-tier system model(client-server), VGFF(Virtual GIS File Format), internal GIS import, Feature manager(zoning, layering, visualization evironment), Scene manager(manage 3D geographic world), Scene editor, Spatial analyzer(Intersect, Buffering, Network analysis), VRML exporter. While, most other 3D GISes or cartographic mapping systems may be categorized into 3D visualization systems handling terrain height-field processing, 2D GIS extension modules, or 3D geometric feature generation system using orthophoto image: actually, these are eventually considered as several parts of "real 3D GIS". As well as these things, other components, especially web-based 3D GIS, are being implemented in this study: Surface/feature integration, Java/VRML linkage, Mesh/Grid problem, LOD(Level of Detail)/Tiling, Public access security problem, 3-tier architecture extension, Surface handling strategy for VRML.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.925-938
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• 2010

Depending on network conditions, a communication network could be overloaded when media are transmitted. Research has been carried out to lessen network overloading, such as by filtering, load distribution, frame dropping, and other methods. Among these methods, one of the most effective is frame dropping, which reduces specified video frames for bandwidth diminution. In frame dropping, B-frames are dropped and then I- and P-frames are dropped, based on the dependency among the frames. This paper proposes a scheme for protecting copyrights by encryption, when frame dropping is applied to reduce the bandwidth of media based on the MPEG-4 file format. We designed two kinds of frame dropping: the first stores and then sends the dropped files and the other drops frames in real time when transmitting. We designed three kinds of encryption methods using the DES algorithm to encrypt MPEG-4 data: macro block encryption in I-VOP, macro block and motion vector encryption in P-VOP, and macro block and motion vector encryption in I-, P-VOP. Based on these three methods, we implemented a digital rights management solution for MPEG-4 data streaming. We compared the results of dropping, encryption, decryption, and the quality of the video sequences to select an optimal method, and found that there was no noticeable difference between the video sequences recovered after frame dropping and the ones recovered without frame dropping. The best performance in the encryption and decryption of frames was obtained when we applied the macro block and motion vector encryption in I-, P-VOP.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.6
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• pp.657-668
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• 2002

Software life cycle consists of requirement analysis, design, implementation, and maintenance phases, and the product of each phase has various format. The UML normalizes such products, and the class diagram, use case diagram, activity diagram and collaboration diagram are usually used for the requirement analysis phase. Because most of UML development tools store such diagrams in a file, there nay be some difficulties of information retrieval and co-work among users. To cope with the difficulties, this paper proposes a database supported methodology to store and manage the diagrams produced by the requirement analysis. In this methodology, the constituents of class, use case, activity and collaboration diagram are first analyzed and then transformed in the form of relational fables. The constituents of such diagrams are stored as tables in a database, and can be easily retrieved from the database by using some queries. This database supported methodology provides the concurrent sharing and high reuse of diagrams.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6C
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• pp.512-519
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• 2008

The proof of a cellular phone used to a crime important data of a criminal investigation and legal judgment become. A lot of on a process use the file format that do not become that is kind of various cellular phones and model pipe, and collect criminal proof, and to analyze be difficult. Also, standardization is not made, and can be adopted on procedures from confiscation search processes regarding a cellular phone to integrity extractions of Forensic data in courts in the confiscation criminal investigation spots. Standardize confiscation search procedures of a cellular phone at these papers. Use a radio waves interception envelope and radio waves interception device for a movement which a security does integrity of criminal on-site cellular phone confiscation search data by standard procedures, and was devoted to. Analyze corroborative facts of a cellular phone seized, and verify integrity, and present problems regarding cellular phone confiscation search procedures and measures, and will contribute in development of Mobile Forensic through integrity damage experiment.

• The Journal of the Korea Contents Association
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• v.18 no.1
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• pp.305-313
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• 2018

Public open data is a database or electronic file produced by a public agency or government. The government is opening public data through the open data portals and individual agency websites. However, it is a reality that there is a limit to search and utilize desired public data from the perspective of data users. In particular, it takes a great deal of effort and time to understand the characteristics of data sets and to combine different data sets. This study suggests the possibility of interlinking between data sets by analyzing the common relationship of item names held by public data. The data sets are collected from the open data portal, and item names included in the data sets are extracted. The extracted item names consist of formal context and formal concept through formal concept analysis. The format concept has a list of data sets and a set of item name as extent and intent, respectively, and analyzes the common items of intent end to determine the possibility of data connection. The results derived from the formal concept analysis can be effectively applied to the semantic connection of the public data, and can be applied to data standard and quality improvement for public data release.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.5
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• pp.959-970
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• 1994

In this thesis, a printed score is read by using handy scanner and the recognition process is excuted in parallel, finally, on Mesh-Connected Computer. What is read is classified into certain patterns and is recognized, based on knowledge. The preprocessing steps are minimized and simple operations are used in the algorithm proposed in this thesis. The score symbols on a printed score can be recognized irrespective of their sizes but their diversity males it difficult to recognize them all, so it is programmed so as to recognize some symbols that is used necessarily and frequently. The recognized result is transformed into the MIDI standard file format. It is required to use a parallel processing system with multiprocessors because the high speed image processing is required. A digitized two-dimensional image is appropriate in processing on the SIMD Mesh-Connected Computer(MCC). Therefore, we explain this architecture and present parallel algorithm using SIMD MCC with n processors that achieves time complexity0(n).

• Journal of Digital Contents Society
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• v.11 no.4
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• pp.579-588
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• 2010

Generalization of the web, development of one-person media such as the blog and mini homepage, and integration of video digital devices have generalized multimedia video services on the web. However, flash videos, the previously used bit map-based multimedia videos, exhibit problems like the waterfall phenomenon, lag phenomenon, or non-synchronization of audios or videos. Thereupon, This study is conducted to suggest a converting technique to provide efficient web video service on the web by solving problems of bitmap-based flash video through file format-converting software and movie editing programs. And this paper also conducts experiments on five videos for 13 CODECs and analyzes converted results comparatively. The recommendable method considering the characteristics of each videos is to utilize MainConcept H.264 Video CODEC using SWF2Video pro. The result of this research can be used to produce web videos on the web more effectively.

• Journal of the Korea Society of Computer and Information
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• v.19 no.2
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• pp.91-99
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• 2014

This paper is about design and implementation of 'SeaMap' importer module which is for map-based application using 'SeaMap' data. 'SeaMap' data importer is a module that reads 'SeaMap' data in consistent form and offers using easily change the format and the internal data structure in the application. Design of data importer module is based on analyzing characteristic of 'SeaMap'. The comparative analysis between the data type of 'SeaMap' and standard S-57 Electronic Navigation Chart (ENC) of the International Hydrographic Organization (IHO), based on this, to be applicable of S-52 standards 'SeaMap' data is defined as a structure of data. The importer module is designed and converted to allow to use distribution type of 'SeaMap' data sets in map application, parsing 'SeaMap' data around the object defining transformation data structure. In addition, we implemented a 'SeaMap' data viewer in order to test our 'SeaMap' data importer module.