• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.200-212
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• 2004

Electronic Navigational Chart is a sophisticated digital chart which contains navigational information such as coastline, depth of water, and nautical mark. It contains high levels of textual, spatial and graphical data, and rapidly replaces traditional paper charts. Although Electronic Navigational Chart has been successfully applied to the navigation of ships, the specific data format, S-57, requires some specialized systems. Furthermore its usage may be limited to specific domains and experts with restrictions. To overcome these limitations resulting from the specific data format, S-57, of Electronic Navigational Chart, more general data format such as XML will be preferred. If Electronic Navigational Chart is transformed into the form of XML, it can be easily accessed and exchanged on the internet. Therefore it may be used for more users and applications. In this paper, we propose an XML. Schema to equivalently represent XML for the S-57 format of Electronic Navigational Chart and develop a program translating the S-57 Electronic Navigational chart to XML document according to the proposed XML schema.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.5
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• pp.1107-1115
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• 2017

The most commonly used PKZIP format is a ZIP file, as well as a file format used in MS Office files and application files for Android smartphones. PKZIP format files, which are widely used in various areas, require structural analysis from the viewpoint of digital forensics and should be able to recover when files are damaged. However, previous studies have focused only on recovering data or extracting meaningful data using the Deflate compression algorithm used in ZIP files. Although most of the data resides in compressed data in the ZIP file, there is also forensically meaningful data in the rest of the ZIP file, so you need to restore it to a normal ZIP file format. Therefore, this paper presents a technique to recover a damaged ZIP file to a normal ZIP file when given.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.1
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• pp.87-98
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• 2008

Electronic Navigational Charts (ENCs) are digital charts encoded in S-57 format, which contain navigational informations such as coastlines, depth areas, and nautical marks. Although they have been successfully used for the safe navigation of ships, they have limited usages and applications because of their specialized data format and access systems. To cope with such drawbacks, S-57 ENCs need to be transformed into more generalized format such as Geography Markup Language (GML). The transformed GML ENCs can be kept in a database for efficiency, and can be accessed through Internet for usability. This paper proposes a new method for transforming and managing ENCs with XML database. S-57 ENCs are lust transformed into GML format, and then stored in a XML database. On the database, users can query for their needs. To validate the feasibility of the proposed method, we developed a protype system, and then conducted several test runs. The system can provide users with easy access to the marine information contained in ENCs. It also provides compatibility and efficiency by virtue of GML and XML database, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.1
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• pp.170-191
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• 2024

The transmission of confidential data using cover media is called steganography. The three requirements of any effective steganography system are high embedding capacity, security, and imperceptibility. The text file's structure, which makes syntax and grammar more visually obvious than in other media, contributes to its poor imperceptibility. Text steganography is regarded as the most challenging carrier to hide secret data because of its insufficient redundant data compared to other digital objects. Unicode characters, especially non-printing or invisible, are employed for hiding data by mapping a specific amount of secret data bits in each character and inserting the character into cover text spaces. These characters are known with limited spaces to embed secret data. Current studies that used Unicode characters in text steganography focused on increasing the data hiding capacity with insufficient redundant data in a text file. A sequential embedding pattern is often selected and included in all available positions in the cover text. This embedding pattern negatively affects the text steganography system's imperceptibility and security. Thus, this study attempts to solve these limitations using the Part-of-speech (POS) tagging technique combined with the randomization concept in data hiding. Combining these two techniques allows inserting the Unicode characters in randomized patterns with specific positions in the cover text to increase data hiding capacity with minimum effects on imperceptibility and security. Format-preserving encryption (FPE) is also used to encrypt a secret message without changing its size before the embedding processes. By comparing the proposed technique to already existing ones, the results demonstrate that it fulfils the cover file's capacity, imperceptibility, and security requirements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9B
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• pp.1126-1142
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• 2011

This paper addresses the stereoscopic 3D broadcasting technology that delivers the 3DTV contents through the digital cable networks. In order to convey the 3D contents via DCA TV network, specifications of 3D video format, compression, multiplexing, signalling and transport are to be developed. Since 3D has some constraints unlike 2D, it is required to be well designed by considering the capacity of the additional view and the backward/forward compatibility. This paper goes with the latest trends of 3D standard, requirements and service scenarios and then covers the 3D format, compression, multiplexing and signaling, service information and transport/reception technologies.

• Journal of Satellite, Information and Communications
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• v.11 no.2
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• pp.23-28
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• 2016

In this paper, we proposed the novel algorithm which controls the resolution of the HDMI(High Definition Multimedia Interface) by the channel estimation from WiFi-AP(Access Point) in the ISM(Industry-Science-Medical) band. The 2.4 and 5 GHz channel models are widely used since they have identical RF property as RSSI(Received Signal Strength Indication). Especially, the performance degradation of signal-transmission and streaming of WiFi will be occurred by the co-channel interference between AP(Access Point) and increased number of smart devices. Therefore, the optimization scheme of video format timing was designed by HDMI-CEC(Consumer Electronics Control) which considers the transmission speed of radio channel. The HDMI resolution, video quality of home-gateway and digital TV and the decision of PIP position can be maintained by the protocols between smart devices and DLNA(Digital Living Network Alliance) via proposed technique.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.531-541
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• 2017

Realistic videos using multi-view videos are created so that the contents shown on multi-view displays or screens look realistic. These images have been mostly used for special videos for exhibition, but, recently, systems such as Screen X have given rise to multi-view images as a format for storytelling contents such as movies. This study used HD-level broadcasting digital video camera with three zoom lenses for shooting wide to close-up shots focusing on a person, in the same way as Screen X, and identified and analyzed problems found during multi-view image registration correction. The results of this study suggested, provided the shooting technique and equipment are improved, the multi-view format can be used for conveying stories and information. Future research will need to investigate and supplement relevant techniques that will enable production of high-quality multi-view image contents by using a cinema-grade camera with standard lenses, instead of using broadcasting-grade zoom lenses.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.199-203
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• 1999

This paper is on the DSP system design and implementation for real time MPEG-2 AAC multichannel audio, and MPEG-4 object oriented audio coding. This DSP system employs two DSPs of the state of the art TMS320C6701, developed by TI semiconductor. DSP board has PCI interface for downloading application program and control the system. DSP board was designed to use for both encoder and decoder, by setting several switches. The system contains external input and output box also, for A/D and D/A conversion for eight channel audio. The input box converts multi channel digital audio to ADI format, that provides serial interface for eight channel digital audio. And the output box converts ADI format signal to multi channel audio. Through this ADI interface, DSP boards can be connected to input, output box. Implemented DSP system was tested for integration with MPEG-2 AAC encoder and decoder S/W. Currently the DSP system performs realtime AAC 4-channel audio encoding with two DSPs, and 8-channel decoding with one DSP.

• Journal of Digital Convergence
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• v.19 no.1
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• pp.389-399
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• 2021

The research background of this paper is because the u-convergence information system applying flow theory lacks the measurement of tourist satisfaction. The purpose and research method of this study are as follows. The first is the suggestion of flow relation information display format algorithm. Second, by combining this algorithm and flow theory, a pattern algorithm was created according to the content information quality and the personality type of tourists. The expected effect of this study is to derive the success factors of the u-convergence information system by generating a pattern algorithm according to the flow relationship information display format and the tourist's personality type. The limitations of this paper are limited to one area, and objectivity is poor due to the lack of data and small area. In the future, it is necessary to evaluate the effectiveness through analysis after applying the method presented to other tourist destinations. Future tasks will need to be supplemented with data from expert groups and objectivity in various regions.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.E2
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• pp.66-73
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• 2007

The introduction of tracer gas techniques to ventilation studies in indoor environments provides valuable information that used to be unattainable from conventional testing environments. Data acquisition systems (DASs) containing analogue-to-digital (A/D) converters are usually used to function the key role that records signals to storage in digital format. In the testing process, there exist a number of components in the measuring equipment which may produce system-based inference to the monitored results. These unwanted fluctuations may cause significant error in data analysis, especially when non-linear algorithms are involved. In this study, a pre-processor is developed and applied to separate the unwanted fluctuations (noise or interference) in raw measurements and to reduce the uncertainty in the measurement. Moving average, notch filter, FIR (Finite Impulse Response) filters, and IIR (Infinite Impulse Response) filters are designed and applied to collect the desired information from the raw measurements. Tracer gas concentrations are monitored during leakage and ventilation tests in the model test room. The signal analysis functions are introduced to carry out the digital signal processing (DSP) work. Overall the FIR filters process the $CO_2$ measurement properly for ventilation rate and mean age of air calculations. It is found that, the Kaiser filter was the most applicable digital filter for pre-processing the tracer gas measurements. Although the IIR filters help to reduce the random noise in the data, they cause considerable changes to the filtered data, which is not desirable.