• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1342-1350
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• 2009

In accordance with the development of broadcasting, the style of using medium by users has been personalized in the propensity to consume. Recent advent of media convergence allowed users of medium to decide the received environment for their needs, thereby the position of users has become more important in the medium consumption. IPTV has the most advanced form of personalized information media. However, IPTV was made by media convergence, which has relation with a variety of interested parties, so there are a few troubles among them in the way of commercializing IPTV. As a matter of fact, although users play a leading role in the IPTV industry, there are still few discussions on the welfare of users. IPTV should be remained the characteristic of the medium of personalized information, and it should include the welfare of users in various fields of media convergence. That is Universal Service. It is necessary to be guaranteed the access right and the variety of contents in using IPTV. Moreover, in terms of telecommunication, IPTV should insure the reasonable fare system as a pay-services. On the basis of the analysis in local and international IPTV circumstances, in terms of content as a medium of personalized information, in terms of fares as a pay-services, and in terms of digital literacy as a new medium of digital access, policies for welfare of users are suggested.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.18-23
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• 1999

A numerical model of flow velocity in the standing water system is presented. This model(RMA-2), based on the 2-dimensional unsteady momentum and continuity equations, uses finite element techniques to simulate the distribution of velocity over a spatial location of lakes. The present model represents an improvement over existing numerical water quality models in that it can model the unsteady state and can, therefore, cope with time with a spatial location of standing waters such as lakes and large reservoirs. The model thus allows the engineer to do more accurate estimation of water flows and thus water qualities in standing waters where directions and velocities of the flow become more important for the simulation of the water quality than in running waters. Tests for the data collected in the lake "Paldang" indicates that the model works well under limited circumstances. However, to be more accurate estimation of velocity with the present model, accumulation of data for the measurement of velocities and renovation of geometrical conditions of the lake would be needed.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.193-198
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• 1997

The purpose of this study was to find out a suitable resin to remove $NO_3-N$ from groundwater. Four different commercial resins differentiated by type, porosity and nitrate selectivity were used to compare the performance of nitrate removal. Gel type, Type 2 anion exchange resin was preferable when anion concentration of raw water was low. But efficiency of this resin decreased as flow rate increased. However, macroporous type resins were not affected by increasing flow rate. Macroporous resins were preferable when anion concentrations in raw water were high and high flow rate was proposed. And the general type resin showed better efficiency when sulfate concentrations were low. However the nitrate selective resin had better efficiency in treating raw water of high sulfate concentration. From the results, it may be drawn that nitrate selective resins are preferable to general type when a sulfate concentration in groundwater is over 50mg/l.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.232-236
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• 2005

This study was performed to find out the patterns of Listeria spp. contamination during Kimbab preparation at the specialized restaurants. Samples were collected from ingredients, containers, equipments, and environments from two Kimbab restaurants from July through September, 2004. Isolation rate of Listeria spp. was $43.2\%$ among 264 samples. Strains isolated were Listeria innocua $35.9\%$, L. murrayi $6.8\%$, and L. grayii $0.3\%$. No L. monocytogenes was detected. Contamination level of ingredients, containers, equipments, and Kimbab sampled during afternoon was all significantly higher than the samples collected during morning(P < 0.05). The most influencing factor of contamination was improper handling or no disinfection procedures during Kimbab preparation. Safety controls are recommended as follows; prevention of cross-contamination during ingredients Preparation, temperature control for ingredients and Kimbab during holding, cleaning and disinfection of chopping boards and knives during preparation processing, and frequent changes of disposable gloves. Kimbab restaurants should recognize the importance of safety control using the Good Hygienic Practices.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.67-73
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• 1999

This experiment was conducted to investigate the effect of thermokeeping bag with 30 and 45cm width on the growth, fruit quality and yield of oriental melon. Difference of the highest temperature was not observed but the lowest temperature of thermokeeping bag with 30cm and 45cm width was higher than that of control by 0.9$^{\circ}C$ and 1.8$^{\circ}C$, respectively The highest soil temperature of thermokeeping bag with 30cm and 45cm width was higher than that of control by 1.9$^{\circ}C$ and 9.9$^{\circ}C$, respectively and the lowest soil temperature of thermokeeping bag with 30cm and 45cm width was higher than that of control by 0.9$^{\circ}C$ and 1.2$^{\circ}C$, respectively. Growth characteristics in terms of stem length, leaf number, leaf area, fresh and dry weight, fruit weight, flesh thickness and soluble solid were higher as the width of thermokeeping bag was winder. Marketable yield per 10a of 30 and 45cm thermokeeping bag was higher 5.3% and 19.2% than that of control with 996.4kg per 0.1ha.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.173-182
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• 2020

Since 2000, Korea has seen a big trend in the market, as the EU tightened regulations on environment due to global warming, high oil prices and aging rural population distribution, strengthening the need for multi-purpose electric moto vehicles for small farmers based on eco-friendly energy. Multi-purpose electric motor vehicles for rural small businesses will be a very innovative means of transportation, not only maintained at a low cost and to reduce greenhouse gases through the activation of eco-friendly energy, but also be a very innovative means of transportation for reducing the labor intensity of the aging farming industry and transporting night work and logistics. In this paper, with the implementation of eco-friendly energy policies, small and medium-sized rural small business owners can easily operate on unpaved roads and well-drawn farming environments, while the intensity of labor can be reduced when transporting crops also can simply replace parts at a low cost in the event of an accident. To propose rural multi-purpose modular electric vehicles, the existing literature is reviewed and 12 modular parts are presented by benchmarking electric vehicles at home and abroad. This paper is thought to be helpful for the research of the industry as well as the design industry of modular electric vehicles.

• Journal of Environmental Science International
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• v.19 no.8
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• pp.951-960
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• 2010

Sediment works as a resource for electric cells. This paper was designed in order to verify how sediment cells work with anodic material such as metal and carbon fiber. As known quite well, sediment under sea, rivers or streams provides a furbished environment for generating electrons via some electron transfer mechanism within specific microbial population or corrosive oxidation on the metal surfaces in the presence of oxygen or water molecules. We experimented with one type of sediment cell using different anodic material so as to attain prolonged, maximum electric power. Iron, Zinc, aluminum, copper, zinc/copper, and graphite felt were tested for anodes. Also, combined type of anodes-metal embedded in the graphite fiber matrix-was experimented for better performances. The results show that the combined type of anodes exhibited sustainable electricity production for ca. 600 h with max. $0.57\;W/m^2$ Al/Graphite. Meanwhile, graphite-only electrodes produced max. $0.11\;W/m^2$ along with quite stationary electric output, and for a zinc electrode, in which the electricity generated was not stable with time, therefore resulting in relatively sharp drop in that after 100 h or so, the maximum power density was $0.64\;W/m^2$. It was observed that the corrosive reaction rates in the metal electrodes might be varied, so that strength and stability in the electric performances(voltage and current density) could be affected by them. In addition to that, COD(chemical oxygen demand) of the sediment of the cell system was reduced by 17.5~36.7% in 600 h, which implied that the organic matter in the sediment would be partially converted into non-COD substances, that is, would suggest a way for decontamination of the aged, anaerobic sediment as well. The pH reduction for all electrodes could be a sign of organic acid production due to complicated chemical changes in the sediment.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.187-193
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• 1996

This experiment was conducted to investigate the influence of temperature variation by the different ventilation methods on the growth and quality of oriental melon in greenhouse of tunnel type 1. The dropping effect in temperature by ventilation types was best at type 3 and those of type 2, type 1 were in order. 2. The temperature distribution in type 3 was uniformed as air- inflow and air- outflow by wind ventilation were easier than others. Whereas the temperature of type 1 having lateral ventilation hole and type 2 having the zenith ventilation tube and lateral ventilation hole was ascended, because small ventilation area of ventilation tube and hole could not make the gravity and wind ventilation successfully. 3. When compared with air amount of three types ventilated by the temperature difference of outside and inside of tunnel type house, that of type 3 was more than those of type 1 and type 2. 4. Type 3 was better than type 2 and type 1 in lear numbers, leaf area, fruit weight, flesh thickness, malformed fruit rate, and marketable fruit rate. 5. Marketable fruit rate of all treatment at each harvesting stages was rised, as goes to the latter periods.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.109-115
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• 2011

This study was carried out to investigate the plant growth of various ferns affected by the shading and fertilizer application and to recommend the appropriate levels of light intensity. Evergreen ferns like Dryopteris nipponensis Koidz., Cyrtomium falcatum (L. f.) Presl, Onychium japonicum (Thunb.) Kunze and deciduous ferns like Athyrium niponicum (Mett.) Hence, Thelypteris decursive-pinnata Ching, Athyrium brevifrons Kodama ex Nakai were used in this experiment. Evergreen ferns showed the best growth in the shading level of 30~60%. The plant growth and ornamental value (leaf color) of these plants were improved according to the fertilizer application in appropriate shading levels. The survival rate remained constantly in all treatments. Deciduous ferns showed the best growth in different shading levels from 0 to 60%. Some treatments showed improved growth according to fertilizer application, whereas survival rate was in the other treatments. There were differences in plant growth of evergreen and deciduous ferns according to fertilizer application, and additional researches must be executed to explain these reponses.

• Economic and Environmental Geology
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• v.53 no.2
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• pp.159-166
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• 2020

In this research, we investigate the effect of microwave pretreatment on the recovery of gold from the gold concentrates by thiourea leaching. The changes in mineral phases by decomposition of pyrites in the gold concentrates using microwave were observed, and the result of microwave irradiation showed that the temperature of the irradiated sample increases with increasing irradiation time. With the reaction of temperature increases, Sulfur (S) in pyrites was converted to sulfur dioxide (SO₂), and then the content of S in the sample was reduced. The analytical results of XRD and SEM-EDS showed that pyrites are converted to magnetite and hematite, and its surfaces are changed to a porous shape where micro-cracks are developed. The Au leaching efficiency from the irradiated gold concentrates using thiourea-mixed solvent increased with the increases of irradiation time and solvent concentration. The experimental results considering leaching parameters indicate that the mechanism of microwave irradiation increases the maximum leaching efficiency and leaching rate of the gold concentrates, and the solvent does a role for the increasing of leaching rate constant.