• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.4
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• pp.33-42
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• 2019

In this study, the channel and floodplain widths are indirectly measured for three different watersheds using satellite images to reflect the shape of Korean channels in the Soil and Water Assessment Tool (SWAT) model. For measuring the channel and floodplain widths, multiple satellite images were referred to ensure the widest width of certain points. In the single channel, the widths at the multiple points were measured. Based on the measured data, the regression equations were derived to estimate the channel and floodplain widths according to watershed areas. Applying these developed equations, this study evaluated the effect of the change of channel and floodplain widths on the SWAT simulation by comparing to the measured streamflow data. The developed equations estimated larger channel width and smaller floodplain compared with those calculated in the current SWAT model. As shown in the results, there was no considerable changes in the predicted streamflow using the current and developed equations. However, the flow velocity and channel depth calculated from the developed equations were smaller than those of the current equations. The differences were caused by the effect of different channel geometries used for calculating the hydraulic characteristics. The channel geometries also affected the water quality simulation in channels because the hydraulic characteristics calculated by the channel geometries are directly related to the water quality simulation. Therefore, application of the river cross-sectional regression equation reflecting the domestic stream shape is necessary for accurate water quantity / quality and water ecosystem simulation using hydrological model.

• Environmental Engineering Research
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• v.24 no.3
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• pp.463-473
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• 2019

Nanoscale zero-valent iron (nZVI) has proved to be an effective tool in applied environmental nanotechnology, where the decreased particle diameter provides a drastic change in the properties and efficiency of nanomaterials used in water purification. However, the agglomeration and colloidal instability represent a problematic and a remarkable reduction in nZVI reactivity. In view of that, this study reports a simple and cost-effective new strategy for ultra-small (< 7.5%) distributed functionalized nZVI-EG (1-9 nm), with high colloidal stability and reduction capacity. These were obtained without inert conditions, using a simple, economical synthesis methodology employing two stabilization mechanisms based on the use of non-aqueous solvent (methanol) and ethylene glycol (EG) as a stabilizer. The information from UV-Vis absorption spectroscopy and Fourier transform infrared spectroscopy suggests iron ion coordination by interaction with methanol molecules. Subsequently, after nZVI formation, particle-surface modification occurs by the addition of the EG. Size distribution analysis shows an average diameter of 4.23 nm and the predominance (> 90%) of particles with sizes < 6.10 nm. Evaluation of the stability of functionalized nZVI by sedimentation test and a dynamic light-scattering technique, demonstrated very high colloidal stability. The ultra-small particles displayed a rapid and high nitrate removal capacity from water.

• Korean Journal of Ophthalmology
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• v.32 no.6
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• pp.445-450
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• 2018

Purpose: To compare the tear film lipid layer thickness (LLT) between patients with incomplete nasolacrimal duct obstruction (NLDO) and normal controls and to analyze the changes in tear film LLT and blinking pattern after silicone tube intubation in NLDO patients. Methods: We reviewed the medical records of 68 eyes in 52 incomplete NLDO patients who underwent silicone tube intubation from January 2017 to July 2017. The LLT, blinking pattern, and Meibomian gland image were measured with the LipiView II ocular surface interferometer. The Meibomian gland drop-out ratio was measured using the polygon selection tool in the Image J program. Tear meniscus height, which is the other lacrimal indicator, was assessed with spectral-domain optical coherence tomography. Results: Tear meniscus height was significantly decreased after silicone tube intubation (p < 0.01). Preoperative minimum, maximum, and average LLT values were $62.4{\pm}24.0$, $86.7{\pm}17.9$, and $71.7{\pm}23.3nm$, respectively. Significant changes in the minimum, maximum, and average LLT ($74.8{\pm}23.6$, $98.8{\pm}11.0$, and $91.6{\pm}16.1nm$, respectively) were observed after silicone tube intubation (p < 0.001, p = 0.001, and p < 0.001). The partial blinking/total blinking ratio in 20 seconds and the Meibomian gland drop-out ratio showed no significant change after silicone tube intubation. Conclusions: Overall, the LLT was increased after silicone tube intubation. Silicone tube intubation may be helpful in maintaining LLT with a normalized of amount of tears.

• Journal of the Korean GEO-environmental Society
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• v.19 no.12
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• pp.65-72
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• 2018

The uses of unmanned aerial vehicles (UAV) have been expanding in agriculture surveys, obtaining real time updates of dangerous facilities where human access is difficult, disaster monitoring, and 3D modeling. In reality, there is an upsurge in the application of UAVs in fields like, construction, infrastructure, imaging, surveying, surveillance and transportation. Especially, when the slope failure such as landslide occurs, the uses of UAVs are increasing. Since, the UAVs can fly in three dimensions, they are able to obtain spatial data in places where human access is nearly impossible. Despite of these advantages, however, the uses of UAVs are still limited during slope failure. In order to overcome these limitations, this study computes the soil volume change during slope failure through the computation technique using photogrammetric information obtained from UAV system. Through this study, it was found that photogrammetric information from UAV can be used to acquire information on amount of earthworks required for repair works when slope collapse occurs in mountainous areas, where human access in difficult.

• The Korean Journal of Archival Studies
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• no.57
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• pp.5-33
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• 2018

Records, especially the authentic records the nation secured, have an ontological feature of proof that is able to persuade the current present of the past present, and inherent in it is faith that originates from fundamental objectivity. Therefore the image of silence that such strictness of records creates realizes the detonation of specific memories through the act of visual exhibition. This research started from the notion that records achieve social vitality and return through its exhibition, as well as the critical awareness that it 're-mediate' the past and memory through interactions with image. The reason for viewing the archival exhibition as the subject of user analyzation is that in the process where exhibition sorts and arranges records, it is the tool and mediation that most distinctly exposes the identity of the archives. Hence, this research first analyzes national archives, particularly the exhibition of "presidential" records, which is in the center of memory conflict, in the viewpoint of the cultural practice of memory. Afterwards, it discusses empirical research and results on how users accept and resist the meaning of the exhibition through actual surveys of users after their viewing of an exhibition.

• Journal of Korea Technology Innovation Society
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• v.22 no.2
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• pp.265-281
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• 2019

With the advent of the Internet-based economy, the dramatic changes in consumption patterns have been witnessed during the last decades. The seminal change has led by Data Technology, the integrated platform of mobile, online, offline and artificial intelligence, which remained unchallenged. In this paper, I use data analysis tool (TexTom) in order to articulate the definitfite notion of data technology from Internet sources. The data source is collected for last three years (November 2015 ~ November 2018) from Google and Naver. And I have derived several key keywords related to 'Data Technology'. As a result, it was found that the key keyword technologies of Big Data, O2O (Offline-to-Online), AI, IoT (Internet of things), and cloud computing are related to Data Technology. The results of this study can be used as useful information that can be referred to when the Data Technology age comes.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.101-106
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• 2019

This paper considers the historicity and aesthetical implications of in the art world of Paul Ryan(1943-2013) who designed the aestheticization of relational circuit of society by realizing the value of social transformation being inherent in video with cultural practices and suggesting the interdisciplinary method of leaning and research in the early video art history. To do this, in Chapter II, I review the first artwork presented firstly in the art gallery exhibition "TV as a Creative Medium" in 1969, in which Ryan proposed a video medium as a communication system and experimented the concept of 'feedback' in Cybernetics. And Chapter III focuses Ryan's discursive activities contributed to magazine Radical Software and artist-collective Raindance Corporation with growing interest in communication technology. At this time, Ryan regarded video medium as the tool for cybernetic expansion. Finally Chapter IV deals with the development of ecological method based on "a shared perception of environmental realities" and verifies Ryan's vision that video medium would be most effective means of social change and communication.

• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1540-1553
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• 2019

A nuclear power plant (NPP) is a highly complex system-of-systems as manifested through its internal systems interdependence. The negative impact of such interdependence was demonstrated through the 2011 Fukushima Daiichi nuclear disaster. As such, there is a critical need for new strategies to overcome the limitations of current risk assessment techniques (e.g. the use of static event and fault tree schemes), particularly through simulation of the nonlinear dynamic feedback mechanisms between the different NPP systems/components. As the first and key step towards developing an integrated NPP dynamic probabilistic risk assessment platform that can account for such feedback mechanisms, the current study adopts a system dynamics simulation approach to model the thermal dynamic processes in: the reactor core; the secondary coolant system; and the pressurized water reactor. The reactor core and secondary coolant system parameters used to develop system dynamics models are based on those of the Palo Verde Nuclear Generating Station. These three system dynamics models are subsequently validated, using results from published work, under different system perturbations including the change in reactivity, the steam valve coefficient, the primary coolant flow, and others. Moving forward, the developed system dynamics models can be integrated with other interacting processes within a NPP to form the basis of a dynamic system-level (systemic) risk assessment tool.

• Journal of the Society of Disaster Information
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• v.15 no.3
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• pp.323-338
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• 2019

Purpose: The purpose of this study is to propose an educational program for enhance safety capability of elementary and middle school students through community mapping application. Method: Developed and utilized a community mapping application that can be easily used for research. After participating in 425 elementary and middle school students, This study analyzed the change of safety competency through survey. Results: Through the community mapping activities, it was possible to derive the actual life surrounding risk factors of the earthy life, and it was found through the questionnaire before and after the activity that the safety competence of the participants improved. Conclusion: Investigation of similar related cases of Public Participant Safety Mapping Tool and analysis of their functionalities are conducted, and user demanded functionalities with improved usability accessability expandability are derived. Also, the system applied the test to elementary and middle school students and the survey showed that the safety capacity was improved according to Safety Mapping activities. This is proposed as a safety education program.

• The Korean Journal of Archival Studies
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• no.31
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• pp.139-161
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• 2012

Donald K. Sebera model can quantitatively compare the preserving environment by calculating the preserving valuation index with changing only the temperature and humidity. In this study, Donald K. Sebera model was used in order to compare and evaluate the preserving valuation index on the best condition and the worst condition in the temperature and humidity range of public records management act. As the results, the preserving valuation index in the best conditions was larger 2.47 times than the worst conditions within the preserving environment permitted in public records management act. Also, the influence of the humidity on the preserving valuation index of a paper archives as decreasing the activation energy for the hydrolysis reaction was larger rather than temperature. Thus the preserving valuation index can easily evaluate the suitability of the temperature and humidity conditions for preserving a archives. Therefore it can be used as useful tool for preservation of archives on change of the temperature and humidity.