• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.4
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• pp.424-432
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• 2016

World's leading countries are developing next generation digital broadcasting system specifications to support UHDTV (ultra-high definition television) contents and other various services. In order to maximize the transmission capacity by using the bandwidth efficiently, most broadcasting systems adopt MIMO-OFDM. In distributed-MIMO systems, multiple transmit antennas are spatially separated and therefore result in multiple timing offsets. To overcome this problem, this paper proposes a technique using a null symbol to detect each individual signal from distributed transmit antennas. By inserting null symbols before preambles, the receiver can distinguish the signals between each transmit antennas and perform frame synchronization. When the reception time difference is shorter than 500 samples, the proposed method outperforms the conventional method.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.115-126
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• 2006

The purpose of this study is to develop an urban inundation model using GIS(geographic information system). The model is combining a storm sewer system model and a overland-flow model for the estimation inundation depth in urban area caused by the surcharge of storm sewers. SWMM(storm water management model) was employed to resolve the storm sewer flow and to provide the overflow hydrographs caused by the failure of a drainage system due to the shortage of drainage capacity. The level-pool overland-flow model and DEM based overland-flow model were used to calculate the detail inundation zones and depths due to the surcharge on overland surface. The simulation results can help the decision preventing flood damages by redesigning and enlarging the capacities of storm sewer systems in the inundation-prone areas. The model can also be applied to make the potential inundation area map and establish flood-mitigation measures as a part of the decision support system for flood control authority.

• Journal of the Korea Society of Computer and Information
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• v.10 no.5 s.37
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• pp.65-76
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• 2005

A digital video is a very long data that requires large-capacity storage space. As such, prior to watching a long original video, video watchers want to watch a summarized version of the video. In the field of sports, in particular, highlights videos are frequently watched. In short, a highlights video allows a video watcher to determine whether the highlights video is well worth watching. This paper proposes a scheme for creating soccer video highlights using the structural features of captions in terms of time and space. Such structural features are used to extract caption frame intervals and caption keyframes. A highlights video is created through resetting shots for caption keyframes, by means of logical indexing, and through the use of the rule for creating highlights. Finally, highlights videos and video segments can be searched and browsed in a way that allows the video watcher to select his/her desired items from the browser.

• Journal of The Korean Association of Information Education
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• v.21 no.2
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• pp.171-181
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• 2017

Each City & Provincial office of education has provided educational informatization training, which invites its partner country's teachers as part of 'e-Learning Globalization Project.' The purposes of this training program are, a) improving nation brand power by maintaining e-learning national competitiveness and strengthening influence, b) solving digital divide by sharing Korean best practices, c) establishing partnership through exchanges and cooperation, d) capacity building which support partner country's leading teachers can play key roles to spread educational informatization in their own country. It is necessary to reflect outcomes of training program until now and to find sustainable development plan, at 10th anniversary of Education ICT training program now. In order to fulfil purposes, qualitative research was conducted to analyze current status based on context, input, process, and product phases, and to find sustainable development alternative. In-depth interview(IDI) was conducted among supervisor, officials, and teachers from partner countries. Also, the result of IDI was analyzed by themes.

• Convergence Security Journal
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• v.14 no.7
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• pp.91-99
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• 2014

NFC(Near Field Communication) is a wireless data exchange technology in 13.56MHz frequency band between devices. The NFC Forum defines the NDEF(NFC Data Exchange Format) exchanging data format between NFC devices and NFC Tags, the NFC RTD(Record Type Definition) defining the record types in the NDEF messages, the Smart Poster RTD in order to replace current paper posters and the Signature RTD to ensure the authenticity and integrity for NDEF records. But the previous smart poster authentication scheme have the weaknesses of using the PKI(Public Key Infrastructure) with certificates to verify the public key for the smart poster authentication and requiring the additional storage capacity of NFC tags for the authentication path. Therefore in this paper we propose a smart poster authentication scheme and implementation based on the authentication URL, a digital signature and a public key without the PKI and certificates for the smart poster authentication.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.118-127
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• 2014

DNA data storage refers to any technique for storing massive digital data in base sequence of DNA and has been recognized as the future storage medium recently. This paper presents an information hiding method for DNA data storage that the massive data is hidden in non-coding strand based on DNA steganography. Our method maps the encrypted data to the data base sequence using the numerical mapping table and then hides it in the non-coding strand using the key that consists of the seed and sector length. Therefore, our method can preserve the protein, extract the hidden data without the knowledge of host DNA sequence, and detect the position of mutation error. Experimental results verify that our method has more high data capacity than conventional methods and also detects the positions of mutation errors by the parity bases.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.10 s.101
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• pp.1043-1049
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• 2005

In OFDM system suitable for high capacity high speed broadband transmission, ICI caused by phase noise degrades system performance seriously by destroying the orthogonality among subcarriers. In this paper, a new STFBC method combining ICI self cancellation scheme and antenna, time, frequency diversity is studied to reduce ICI effectively. CPE and ICI are analyzed by the phase noise linear approximation method in the proposed STFBC OFDM system. CIR, PICR and BER are discussed to compare the system performance degraded by phase noise of PLL. As results, STFBC method significantly reduces ICI. Furthermore, the SCI that usually happens in the traditional STBC, SFBC diversity coding method can be easily avoided.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.2
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• pp.55-61
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• 2012

The primary factors of the LOS(Line-of-Sight) analysis process are terrain height, camera capacity, and canopy cover. The canopy cover rate differs depending on the changing season, and its value is influenced by the tree density, tree height, and etc. This study generated the canopy cover value based on relationship between NDVI(Normalized Difference Vegetation Index) and DMT(Density Measure % of Tree/Canopy Cover), which is a digital map attribute, and then performed the LOS analysis on six station of test sites. As results, It was found that NDVI and DMT are correlated with each other through the experiments. Based on this finding, new DMT map can be generated using NDVI. Also, There is a difference between the result of visibility analysis using the present DMT and one using a new DMT. Especially, the spatial distributions of the detected visible areas are significantly different between the two visibility analysis results.

• Ocean and Polar Research
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• v.31 no.1
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• pp.97-110
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• 2009

Two of the most important topics of the 21st century are ensuring harmony between man and his environment and the emerging long-tail economy in which niche markets are becoming increasingly more important. Since the Industrial Revolution in 17th century, human beings have increasingly exploited the world's natural capital, such as the natural environment and its ecosystems. Now the world is facing limits to sustainable economic growth because of limits to this natural capital. Thus, most countries are beginning to adopt a new development paradigm, the so-called"Green Development Paradigm" which pursues environmental conservation in parallel with economic growth. Recently, the Korean government announced an ambitious national policy of Low Carbon & Green Growth for the next six decades. This is an important step that transforms the existing national policy into a new future-oriented one. The fisheries sector in particular has great potential for making a substantial contribution to this national policy initiative. For example, the ocean itself with its sea plants and phytoplankton has an enormous capacity for fixing carbon, and its vast areas of tidal flats have a tremendous potential for cleaning up pollutants from both the sea and the land. Furthermore, the fishing industry has great potential for the development of fuel-saving biodegradable technologies, and a long-tail economy based on digital technologies can do much to promote the production and consumption of green goods and services derived from the oceans and the fisheries. In order for this potential to be realized, the fisheries authority needs to develop a new green-growth strategy that is practical and widely supported by fishing communities and the markets, taking into account the need for greenhouse gas reduction, conservation of the ocean environment and ecosystems, an improved system for seafood safety, the establishment of strengthened MCS (monitoring control surveillance) system, and the development of coastal ecotourism. In addition, fisheries green policies need to be implemented through a well-organized system of government aids, regulations and compensation, and spontaneous (voluntary) orders in fishing communities should be promoted to encourage far more responsible fisheries.

• Architectural research
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• v.17 no.3
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• pp.109-115
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• 2015

The dynamic pricing of electricity, where the electricity rate increases in a time zone with a high demand for electricity is typically applied to a building whose power reception capacity is greater than a certain size. This includes the time of use(TOU) electricity pricing in Korea which can induce the effect of reducing the power demand of a building. Meanwhile, a VRF (Variable Refrigerant Flow) system that uses electricity is regarded as one of the typical heating and cooling systems along with central air conditioning (central HVAC) for its easy operation and application to the building. Thus, to reduce power energy and operating costs of a building in which the TOU and VRF systems are applied simultaneously, we suggested a control for changing the indoor temperature setting within the thermal comfort range or limiting the rotational speed of an inverter compressor. In this study, to describe the features of the above-mentioned control and verify its effects, we evaluated the results obtained from the analysis of its operation data. Through the actual measurements in winter operations for 73 days since mid- December 2014, we confirmed a reduction of 10.9% in power energy consumption and 12.2% in operating costs by the new control. Also, a reduction of 13.3% in power energy consumption was identified through a regression analysis.