• Journal of the Mineralogical Society of Korea
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• v.15 no.3
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• pp.231-240
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• 2002

Microbial metal reduction influences the biogeochemical cycles of carbon and metals as well as plays an important role in the bioremediation of metals, radionuclides, and organic contaminants. The use of bacteria to facilitate the production of magnetite nanoparticles and the formation of carbonate minerals may provide new biotechnological processes for material synthesis and carbon sequestration. Metal-reducing bacteria were isolated from a variety of extreme environments, such as deep terrestrial subsurface, deep marine sediments, water near Hydrothemal vents, and alkaline ponds. Metal-reducing bacteria isolated from diverse extreme environments were able to reduce Fe(III), Mn(IV), Cr(VI), Co(III), and U(VI) using short chain fatty acids and/or hydrogen as the electron donors. These bacteria exhibited diverse mineral precipitation capabilities including the formation of magnetite ($Fe_3$$O_4$), siderite ($FeCO_3$), calcite ($CaCO_3$), rhodochrosite ($MnCO_3$), vivianite [$Fe_3$($PO_4$)$_2$ .$8H_2$O], and uraninite ($UO_2$). Geochemical and environmental factors such as atmospheres, chemical milieu, and species of bacteria affected the extent of Fe(III)-reduction as well as the mineralogy and morphology of the crystalline iron mineral phases. Thermophilic bacteria use amorphous Fe(III)-oxyhydroxide plus metals (Co, Cr, Ni) as an electron acceptor and organic carbon as an electron donor to synthesize metal-substituted magnetite. Metal reducing bacteria were capable of $CO_2$conversion Into sparingly soluble carbonate minerals, such as siderite and calcite using amorphous Fe(III)-oxyhydroxide or metal-rich fly ash. These results indicate that microbial Fe(III)-reduction may not only play important roles in iron and carbon biogeochemistry in natural environments, but also be potentially useful f3r the synthesis of submicron-sized ferromagnetic materials.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.96-107
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• 2011

Recently, studies of 3D HDTV broadcasting technology have been processed actively. Korea is making efforts to modify Advanced Television Systems Committee (ATSC) 8-Vestigial Side Band (8-VSB) systems for terrestrial 3D HDTV broadcasting services. We intend to adopt a new frame structure to use PN (Pseudo-Noise) sequence as frame header, and VSB modulation. PN sequence is used to recover carrier freqeuncy offset, carrier phase error. In this paper, we will describe this system as the modified ATSC systems. The receiver of the modified ATSC system should be able to estimate and recover carrier frequency offset exactly. A existing ATSC systems inserts pilot to recover carrier frequency offset, on the other hand the modified ATSC systems use PN sequence to recovery carrier frequency offset without the use of pilot. In this paper, we introduce carrier frequency recovery (CFR) scheme for the modified ATSC systems. The proposed CFR scheme is composed of coarse CFR scheme using Fitz algorithm and fine CFR scheme using a simple PN sequence correlation algorithm. And, the symbol information of QAM modulated signal is contained in both In-phase (I)channel and Quadrature-phase (Q)channel. However the symbol information of VSB modulated signal is contained in I channel, and Q channel is just Hilbert transform of I channel. For the reason, VSB modulated symbols can not have fixed phase like QAM modulated symbols, and VSB modulated symbols is more sensitive to carrier frequency offset. Therefore we perform phase correction of received PN sequence to improve performance.

• Journal of Broadcast Engineering
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• v.25 no.5
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• pp.758-769
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• 2020

Hybrid broadcasts utilizing heterogeneous networks can provide not only uniform broadcasting services but also various services using broadcast networks and communication networks. In particular, as content is consumed in various countries and regions, demands for personalized services continue to increase, and research on content insertion technology utilizing heterogeneous networks has been actively conducted. The most important technical challenge when inserting content based on heterogeneous networks is that the start of the inserted content, which replaces the original broadcast content at the time of content insertion, should proceed smoothly, and it must be able to accurately return to the original broadcast content. Currently, UHD broadcasting is converted to digital. However, since there is a system that supports the frame rate used in the analog method, when content insertion occurs in a conventional UHD broadcasting service, there is a problem in decoding the broadcast and inserted content. Since the replacement cost of the broadcasting system is astronomical, this paper proposes a content insertion method using by frame control that can support analog methods without replacing transmission equipment.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.2
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• pp.81-92
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• 2011

High resolution seismic profiles (chirp and sparker system) were analyzed for the interpretation of nearshore sedimentary environments of Suyeong Bay, Busan. The sedimentary sequence is classified into three seismic units (SU1a, SU1b, and SU2), overlying acoustic basement, and each units can be defined as erosional and disconformable strata. The lowermost SU1a is characterized by the acoustically parallel and prolonged inner reflections, compared with the upper SU1b displays irregular internal reflectors. The uppermost unit, SU2, is acoustically transparent. The acoustic basement is incised with channels, probably due to the active erosion during the early period of transgression. The acoustic basement deepens eastward in the study area, suggesting primary association with the Suyeong River. The upper SU1a and SU1b units constitute lowland-fill strata. SU2 is widely distributed over the study area. High resolution seismic profiles of Suyeong Bay provide significant information crucial to the interpretation of sedimentary environmental history, which is closely related to the sea level change, estuarine environment and influx of terrestrial sediments from the adjacent rivers.

• Korean journal of communication and information
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• v.56
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• pp.71-85
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• 2011

This thesis reviews the process in which the regulation systems against ownership concentration of newspapers established with the opportunity of legislation of the periodical act in 1987 was reinforced as they were all amended to the newspaper act in 2005 and as they were again amended in 2009 it came to confront crisis in the aspect of press law legislation history. The regulation systems against ownership concentration of newspapers established based on the principle of legality of newspaper function in the Clause 3, the Article 21 of Constitution was reinforced as the newspaper act in 2005 and in 2006 they began to shrink following the Constitution Court decision against newspaper act. As newspaper act and broadcast act are revised in 2009, regulation against combining the management of newspapers with broadcast and regulation against owning multiple number of newspapers came not to exist. Because in this process, the opposition party also allowed limited cross-ownership of newspaper and broadcast, it can be said that the system of newspaper ownership regulation confronted the crisis of dissolution. The instruction of regulation alleviation in a short period of time in spite of the fact that regulation alleviation which allows cross-ownership of newspaper and broadcast is the matter of policy that should be decided after long-term review of the change of media environment and the progress of the power of domination of public opinion is dangerous. Newspapers are strong media with terrestrial broadcast in formation of public opinion on politics. It's because it is difficult to ignore the worry that the power of domination of public opinion of the newspapers which are in oligopoly of newspaper public opinion market can be spreaded to the territory of report broadcast. From the point of view that there is probability for democracy to be ultimately threatened due to the shrink of political Darwinism caused by concentration of media ownership, the alleviation of ownership concentration of newspapers should have premise of long-term social discussion.

• Journal of Broadcast Engineering
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• v.24 no.5
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• pp.879-891
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• 2019

This paper provides performance evaluations of various channel estimation schemes for Advanced Television Systems Committee (ATSC) 3.0 multiple-input multiple-output (MIMO) system under a fixed reception environment. ATSC 3.0 MIMO system can obtain high spectral efficiency and improved reception performance compared to conventional terrestrial broadcasting systems. The ATSC 3.0 MIMO defines Walsh-Hadamard and null pilot encoding algorithms and the amplitude and phase of MIMO pilots are different from those of single-input single-output pilots. At the receiver, linear and discrete Fourier transform (DFT)-based interpolations can be used for the channel estimation. This paper provides the various combinations of the interpolation schemes for channel estimation in time and frequency dimensions, and then analyzes the performance of the various combinations through the computer simulation. The results of computer simulation show that the combination of the linear interpolation in the time dimension and then DFT-based interpolation in the frequency dimension can obtain the best performance among the considered combinations.

• The Journal of the Korea Contents Association
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• v.19 no.7
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• pp.199-210
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• 2019

Virtual Advertising, which was introduced exclusively in sports casting programs in 2010, has enlarged its scope to terrestrial TV networks' sports news, entertainment shows, and dramas by 2015. Such advertising deregulation allows broadcasting business operators to insert more various virtual advertising methods into TV programs. Despite recent evaluation that virtual advertising was deregulated to a large degree, it is still inadequate compared to foreign state of affairs and has a lot of room for growth. Therefore, this research explores a literature review of virtual advertising in other countries and considers possible ways for virtual advertising in Korea to move forward. Additionally, through in-depth interview with seven virtual advertising experts, the research unravels positive and negative impacts of virtual advertising as well as its current state of affairs and struggles. This research also analyses the regulation of virtual advertising and finally explores possible revitalization strategies. The results of the research show that it is necessary to first improve the viewers' favorable concerning virtual advertising in order to revitalize virtual advertising. Revitalization will also require a clarification of regulation as well as a more unified and consistent content review and rating system. Furthermore, it is imperative that data of advertising impact will be accessible to advertisers and that advertising regulation will loosen. Revitalization will also require a clarification of regulation as well as a more unified and consistent content review and rating system. Furthermore, it is imperative that data of advertising impact will be accessible to advertisers and that advertising regulation will loosen. It is necessary to further develop new techniques and creators of virtual advertising. The research suggests strategies and alternative paths for the growth and revitalization of the virtual advertising market in light of recently revised law.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.296-301
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• 2021

This study is a study dealing with the empirical test of standardized multimedia disaster warning broadcasting linked with the next-generation prediction and warning platform and the disaster warning additional data service of terrestrial UHD broadcasting. The next-generation prediction and warning platform used in the demonstration test complies with the CAP-based TTA standardization standard, and the UHD disaster warning additional data service complies with the AEAT standard. As a result of the experiment, when a standardized CAP disaster warning message is issued and delivered to a broadcasting company, a system was established so that it is automatically converted to AEAT, a UHD disaster warning additional data message, and transmitted. The receiver unit was configured by connecting a set-top capable of receiving disaster alert data and a TV with an HDMI cable. When a disaster is announced, the set-top displays the AEAT message on the TV broadcasting screen, customized to the priority of the disaster and the area where it is issued. In addition, incoming messages are displayed in a language suitable for user settings among 5 languages. Additional multimedia functions such as images and alarm sounds could also be linked. In particular, it was confirmed that the receiver message was displayed within 3 seconds of issuing the disaster alert, enabling prompt delivery of the disaster alert.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.2
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• pp.96-109
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• 2021

Since terrestrial input plays a major role in coastal primary production, an understanding of land-ocean coupling (LOC) is key to understand coastal ecological changes. In this study, the LOC has been classified into three stages (i.e., the baseflow, plume event and residual flow). In order to characterize its pattern in Nakdong River estuary, multi-platform data were obtained from remote sensing (geostationary ocean color image (GOCI)), in-situ measurement (marine environment information system (MEIS)), on-site measurement (discharge data and meteorological data). The MEIS data were grouped into three stages of LOC using principal component analysis (PCA), and the LOC (2013 ~ 2018) was examined at each stage using multi-platform data. In the Nakdong River estuary, the maximum value of chlorophyll-a (chl-a) was unexpectedly appeared during the plume event. It is assumed that there was no significant increase in turbidity, expected during the typical plume event, together with the weak flushing effect, caused the enhanced phytoplankton growth. Compared with other estuaries, LOC is common in estuaries affected by freshwater inflow, but LOC has different pattern depending on the size of the plume. While estuaries that form small plumes of about 10 km (low freshwater discharge and weak flushing effect) observed high chl-a in the plume event because the phytoplankton can response to the increased nutrient more rapidly. estuaries that form large plumes of more than 100 km est (high freshwater discharge and strong flushing effect) follow the typical LOC pattern conceptualized in this study (high chl-a in the residual flow).

• Economic and Environmental Geology
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• v.51 no.2
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• pp.185-201
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• 2018

Nuclear power plants(NPP) are constructed and operated to ensure safety against natural disasters and man-made disasters in all processes including site selection, site survey, design, construction, and operation. This paper will introduce a series of efforts conducted in Korea Hydro and Nuclear Power Co. Ltd., to assure the safety of nuclear power plant against earthquakes and other natural hazards. In particular, the present status of the earthquake, fault, and slope safety monitoring system for nuclear power plants is introduced. A earthquake observatory network for the NPP sites has been built up for nuclear safety and providing adequate seismic design standards for NPP sites by monitoring seismicity in and around NPPs since 1999. The Eupcheon Fault Monitoring System, composed of a strainmeter, seismometer, creepmeter, Global Positioning System, and groundwater meter, was installed to assess the safety of the Wolsung Nuclear Power Plant against earthquakes by monitoring the short- and long-term behavioral characteristics of the Eupcheon fault. Through the analysis of measured data, it was verified that the Eupcheon fault is a relatively stable fault that is not affected by earthquakes occurring around the southeastern part of the Korean peninsula. In addition, it was confirmed that the fault monitoring system could be very useful for seismic safety analysis and earthquake prediction study on the fault. K-SLOPE System for systematic slope monitoring was successfully developed for monitoring of the slope at nuclear power plants. Several kinds of monitoring devices including an inclinometer, tiltmeter, tension-wire, and precipitation gauge were installed on the NPP slope. A macro deformation analysis using terrestrial LiDAR (Light Detection And Ranging) was performed for overall slope deformation evaluation.