• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.1
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• pp.47-53
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• 2012

Sensor networks and car networks that have different structure from that of conventional TCP/IP network require extreme network environment due to frequent change of connectivity. Because such extreme network environment has characteristics like unreliable link connectivity, long delay time, asymmetrical data transfer rate, and high error rate, etc., it is difficult to perform normally with the conventional TCP/P-based routing. DTNs (delay and disruption tolerant network) was designed to support data transfer in extreme network environment with long delay time and no guarantee for continuous connectivity between terminals. This study suggests an algorithm that limits the maximum number of copying transferred message to L by improving the spray and wait routing protocol, which is one of the conventional DTNs routing protocols, and using the azimuth and density data of the mobile nods. The suggested algorithm was examined by using ONE, a DTNs simulator. As a result, it could reduce the delay time and overhead of unnecessary packets compared to the conventional spray and wait routing protocol.

• Convergence Security Journal
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• v.6 no.2
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• pp.1-11
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• 2006

The files of intellectual property on computer systems have increasingly been exposed to such threats that they can be flowed out by internal users or outer attacks through the network. The File Outflow Protection System detects file outflow when users not only copy files on client computers into storage devices, but also print them. This Protection system has been designed to Win32 API hooking by I/O Manager in kernel level if files are flowed out by copying. As a result, the monitoring system has exactly detected file outflows, which is proved through testing.

• Journal of Korea Multimedia Society
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• v.21 no.1
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• pp.61-68
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• 2018

In this paper, we present an effective encryption algorithm for 3D printing models in the frequency domain of discrete cosine transform to prevent illegal copying, access in the secured storage and transmission. Facet data of 3D printing model is extracted to construct a three by three matrix that is then transformed to the frequency domain of discrete cosine transform. The proposed algorithm is based on encrypting the DC coefficients of matrixes of facets in the frequency domain of discrete cosine transform in order to generate the encrypted 3D printing model. Experimental results verified that the proposed algorithm is very effective for 3D printing models. The entire 3D printing model is altered after the encryption process. The proposed algorithm is provide a better method and more security than previous methods.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.508-511
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• 2009

The infringement of the copyright is a problem by the distribution of digital contents copied illegally. The digital watermark is expected as a thing preventing unjust copying by burying information in digital data such as image, animation, the sound, TV, radio and movies. [1] [2]But a noise is included in a digital watermark reproduction image. So there is the case that the certification of the reproduction image has difficulty with. If a computer cannot recognize the information reproduced from digital watermarking, the information does not have a meaning. This paper aimed at improvement of the proof of a digital-watermarking reproduction image. And it is verified whether the difference of the form of a character affects the degree of correlation.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.6
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• pp.49-56
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• 2015

To investigate fiber orientation of Korean traditional paper, Hanji, the fiber arrangements on the surface and cross section of Hanji were observed by scanning electron microscope (SEM). The surface observation showed that the fibers of traditional paper were arranged in vertical and horizontal directions, and those of ssangbal sheet forming were arranged more in vertical direction. The fibers of machine made Hanji and copying paper were usually arranged in vertical direction. As for the observation of cross section of traditional paper, fibers arranged in horizontal direction tended to be increased with the increase of thicknesses. The thick traditional paper have cracks in the middle part of structural section of paper. They were larger in cross section in horizontal direction than in vertical direction. The horizontal arrangement of traditional paper seemed to be about 8% to 14% higher to the vertical arrangement, which is very lower to other papers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.676-679
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• 2006

The media transport in automatic office machines such as printers, ATMs, copying machines is achieved by a complicated belt system. The system generally uses a crowning roller and belt which has been well-known for its intrinsic belt centering advantage during its operation. Since the modern office machines require precise high operating speed, stabilization of media transporting system has been one of the important issues of the machine design. Even a minor defect of the belt or the roller in the transport system directly affects its operating stability. This paper delivers a simulation technique that combines a multi-body dynamics analysis routine and a FEM based flexible continuum modeling for the efficient simulation of the flexible media transport problems.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.4 s.109
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• pp.366-371
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• 2006

As functional requirements of automatic office machines like printers, Automatic Tellex Machines(ATMs), copying machines are on a trend for the higher speed and precision, extensive technical advances are being developed and implemented in the industry. Media transport system is a device to convey a sheet of paper in ATMs and printers. The stability of media transport system is a matter of concern as their operating throughput rapidly increases. And defects of belts or rollers in a transport system directly affect the level of stability of the system. Therefore an automatic diagnostic system for predicting various defects is necessary for the stable operation of the media transport system. A simulation based on multi-body dynamics has been done for a feasibility study of a system design for the defect anticipation.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.169-172
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• 2002

Embedding information into video data is a topic that recently gained increasing attention. This paper proposes a new approach for digital watermarking and secure copyright protection of video, the principal aim being to discourage illicit copying and distribution of copyrighted material. The method presented here is based on the three dimensional discrete cosine transform of video scene, in contrast with previous works on video watermarking where each video frame was marked separately, or where only intra-frame or motion compensation parameters were marked in MPEG compressed videos. The watermark sequence used is encrypted, pseudo-noise signal to the video. The performance of the presented technique is evaluated experimentally

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.173-176
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• 2002

This paper proposes a new approach for digital watermarking and secure copyright protection of video. the principal aim being to discourage illicit copying and distribution of copyrighted material. The method presented here is based on the three dimensional discrete wavelet transform of video scene. The watermark is a copyright information encoded in the form of a spread spectrum signal to ensure the system security and is embedded in the 3D DWT magnitude of video chunks. The performance of the presented technique is evaluated experimentally.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.2
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• pp.163-177
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• 2009

The demand for services using digital technology is constantly increasing as new developments in digital consumer electronics and the Internet are made. This is especially true in terms of the demand for IPTV utilizing high speed Internet networks. Research on IPTV threats is important for facilitating financial transactions via IPTV and preventing illegal use or copying of digital content. Thus, this paper analyzes IPTV threats via the IPTV value chain. That is, the distribution system for IPTV service is analyzed along with the components of the value chain and corresponding IPTV security requirements or security technologies, in order to perform a threat analysis and research suitable for the IPTV service environment. This paper has a greater focus on the value chain of the IPTV business than the approach in previous research, in order to analyze security requirements and technologies that are more applicable to the business environment.