• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.19-28
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• 2016

In the case of structural analysis for building structures, the super-structure and the sub-structure are analyzed by using separate structural models in the field because of time saving, facile result interpretation and easy analysis of dynamic behavior. However this separate structural model violated the compatibility condition of structural analysis and it can not consider the interaction of superand sub- structures. In the present study, the analysis results of this separate model were compared to those of the unified model of super- and sub- structures which can consider the interaction of super- and sub- structures and reflect the realistic boundary conditions. According to the comparison results, the the analysis model using separate models can underestimate the member force and deflection of structural members in the super-structures and overestimate the deflection and member force of sub-structures. Therefore, in the case of high-rise buildings, irregular shaped buildings, buildings which are expected to be affected by large differential settlement and remodeling buildings, the unified structural model for super- and sub- structures was recommended for structural analysis instead of the separate structural model.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.1-9
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• 2013

In recent years, numerous mega-size and complex civil infrastructures have been constructed worldwide. For the more precise construction and maintenance process management of these civil infrastructures, the application of a variety of smart sensor-based structural health monitoring (SHM) systems is required. The efficient management of both sensors and collected databases is also very important. Recently, several kinds of database access technologies using Quick Response (QR) code and Augmented Reality (AR) applications have been developed. These technologies provide software tools incorporated with mobile devices, such as smart phone, tablet PC and smart pad systems, so that databases can be accessed very quickly and easily. In this paper, an AR-based structural health monitoring technique is suggested for sensor management and the efficient access of databases collected from sensor networks that are distributed at target structures. The global positioning system (GPS) in mobile devices simultaneously recognizes the user location and sensor location, and calculates the distance between the two locations. In addition, the processed health monitoring results are sent from a main server to the user's mobile device, via the RSS (really simple syndication) feed format. It can be confirmed that the AR-based structural health monitoring technique is very useful for the real-time construction process management of numerous mega-size and complex civil infrastructures.

• Journal of Wetlands Research
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• v.15 no.1
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• pp.35-41
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• 2013

In this study, we tried to overcome a limit in cutting timing of reed culm by applying a plant hormone, indole-acetic acid (IAA) as a growth regulator with various contents ($10^{-3}$ M, $10^{-6}$ M, $10^{-9}$ M, $10^{-12}$ M). 19 shoots emerged from 240 segments of hardened reed culm from montane fen and eight out of the 19 shoots emerged by $10^{-6}$ M IAA treatment as the most in $5^{th}$ Sep. 2012. 50 shoots emerged from 60 segments of non-hardened reed culm from a population in Seoul National University transplanted from Mt. Odae by $10^{-6}$ M IAA treatment despite the cutting was performed about two weeks later ($19^{th}$ Sep.). Via third cutting experiment performed about 40 days later ($29^{th}$ Oct.), only two shoots out of 60 segments were observed by the same experimental condition except atmospheric temperature. It seemed likely that it was too low temperature in third experiment ($10^{\circ}C$) than the former experiments (about $20^{\circ}C$) to form adventitious buds from culm segment. We recommend to utilize the thick reed culm in culm cutting as possible because the thicker culm segment we used, the thicker emerged shoot we could observe (i.e., diameters of emerged shoots were about 20% of the planted segment's diameters).

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.245-257
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• 2016

Although rivers cover only 0.5% of the total land area on the Earth, they are windows that show the integrated effects of watershed biogeochemistry. Studies on the loads and properties of riverine carbon have been conducted because they are directly linked with drinking water quality, and because regional or global net ecosystem production (NEP) can be overestimated, unless riverine carbon loads are subtracted. Globally, ${\sim}0.8-1.5Pg\;yr^{-1}$ and ${\sim}0.62-2.1Pg\;yr^{-1}$ of carbon are transported from terrestrial ecosystems to the ocean via rivers and from inland waters to the atmosphere, respectively. Concentrations, ${\delta}^{13}C$, and fluorescence spectra of riverine carbon have been investigated in South Korea to understand the spatiotemporal changes in the sources. Precipitation as well as land use/land cover can strongly influence the composition of riverine carbon, thus shifting the ratios among DIC, DOC, and POC, which could affect the concentrations, loads, and the degradability of adsorbed organic and inorganic toxic materials. A variety of analyses including $^{14}C$ and high resolution mass spectroscopy need to be employed to precisely define the sources and to quantify the degradability of riverine carbon. Long-term data on concentrations of major ions including alkalinity and daily discharge have been used to show direct evidence of ecosystem changes in the US. The current database managed by the Korean government could be improved further by integrating the data collected by individual researchers, and by adding the major components ions including DIC, DOC, and POC into the database.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1573-1587
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• 2021

A Drone image is an ultra-high-resolution image that is several or tens of times higher in spatial resolution than a satellite or aerial image. Therefore, drone image-based remote sensing is different from traditional remote sensing in terms of the level of object to be extracted from the image and the amount of data to be processed. In addition, the optimal scale and size of data used for model training is different depending on the characteristics of the applied deep learning model. However, moststudies do not consider the size of the object to be found in the image, the spatial resolution of the image that reflects the scale, and in many cases, the data specification used in the model is applied as it is before. In this study, the effect ofspatial resolution and image size of drone image on the accuracy and training time of the semantic segmentation deep learning model of six wintering vegetables was quantitatively analyzed through experiments. As a result of the experiment, it was found that the average accuracy of dividing six wintering vegetablesincreases asthe spatial resolution increases, but the increase rate and convergence section are different for each crop, and there is a big difference in accuracy and time depending on the size of the image at the same resolution. In particular, it wasfound that the optimal resolution and image size were different from each crop. The research results can be utilized as data for getting the efficiency of drone images acquisition and production of training data when developing a winter vegetable segmentation model using drone images.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.373-383
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• 2021

Our society is aging rapidly. In this super-aged society, the increase in healthcare costs are considered a national problem that undermines the sustainability of social security. Various services for healthcare for the elderly have been promoted to address this. However, most of them have focused on healthcare after the outbreak of chronic diseases and lack preventive healthcare. Most of the preventive healthcare projects are only pilots. In this paper, the current status of health care services for senior citizens at home and abroad was analyzed and based on this, the limitations and improvements were analyzed to propose the establishment of IoT-based Total Silver Care Center. IoT-based Total Silver Care Center may be conveniently monitored the health status of the elderly through various sensors, medical devices, and smart bands. And based on this, it can improve the quality of nursing services through time-saving and work efficiency of nursing providers. In addition, health care interventions may be provided in a timely manner if there is a change in the health status of users. And real-time imaging systems can help overcome mental difficulties.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.126-132
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• 2022

Alkaline fuel cells using liquid fuels such as hydrazine and ammonia are gaining great attention as a clean and renewable energy solution possibly owing to advantages such as excellent energy density, simple structure, compact size in fuel container, and ease of storage and transportation. However, common shortcomings including cathode flooding, fuel crossover, side yield reactions, and fuel security and toxicity are still challenging issues. Real time monitoring of fuel concentrations integrated into a fuel cell device can help improving fuel cell performance via predicting any loss of fuels used at a cathode for efficient energy production. There have been extensive research efforts made on developing real-time sensing platforms for hydrazine and ammonia. Among these, recent advancements in electrochemical sensors offering high sensitivity and selectivity, easy fabrication, and fast monitoring capability for analysis of hydrazine and ammonia concentrations will be introduced. In particular, research trend on the integration of metallic and metal oxide nanoparticles and also their hybrids with carbon-based nanomaterials into electrochemical sensing platforms for improvement in sensitivity and selectivity will be highlighted.

• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.119-129
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• 2009

Building construction trends have been changed dramatically in terms of size and mass. With the need to maximize land usage, there has been an increase in the construction of high-rise buildings. This affects not only the entire construction duration and cost, but also subsequent construction activities, such as work to increase underground facilities and in reclamation land area construction. These types of site conditions require soft ground reinforcement and the proper uplift water pressure treatment. In general, two kinds of methods have been used for uplift water pressure treatment systems. However, there have been some problems arising as the result of a lack of research and analysis on underground construction techniques, and a reliance on experiments over actual survey and analysis of site conditions. This paper focused on the problems of conventional selection procedure, by analyzing drawings and proposing a kind of modeling for a reasonable procedure. The results were applied to OO project as a sample construction case to be verified in this research. The initial plan in the case project was the Rock Anchor System. However, as there were terrible miscalculations of basic site conditions that had an extraordinary influence on the underground water level, such as the site's proximity to the Han-river, it was necessary to change the plan to include apermanent drainage system. This achieved a direct construction cost reduction \ 406,702,000 and a maximum sayings of 4% of operational cost, based on the 50-year building Life Cycle Cost.

• Progress in Medical Physics
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• v.24 no.2
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• pp.85-91
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• 2013

At present, megavoltage computed tomography (MVCT) is the only method used to correct the position of tomotherapy patients. MVCT produces extra radiation, in addition to the radiation used for treatment, and repositioning also takes up much of the total treatment time. To address these issues, we suggest the use of a video image-guided setup (VIGS) system for correcting the position of tomotherapy patients. We developed an in-house program to correct the exact position of patients using two orthogonal images obtained from two video cameras installed at $90^{\circ}$ and fastened inside the tomotherapy gantry. The system is programmed to make automatic registration possible with the use of edge detection of the user-defined region of interest (ROI). A head-and-neck patient is then simulated using a humanoid phantom. After taking the computed tomography (CT) image, tomotherapy planning is performed. To mimic a clinical treatment course, we used an immobilization device to position the phantom on the tomotherapy couch and, using MVCT, corrected its position to match the one captured when the treatment was planned. Video images of the corrected position were used as reference images for the VIGS system. First, the position was repeatedly corrected 10 times using MVCT, and based on the saved reference video image, the patient position was then corrected 10 times using the VIGS method. Thereafter, the results of the two correction methods were compared. The results demonstrated that patient positioning using a video-imaging method ($41.7{\pm}11.2$ seconds) significantly reduces the overall time of the MVCT method ($420{\pm}6$ seconds) (p<0.05). However, there was no meaningful difference in accuracy between the two methods (x=0.11 mm, y=0.27 mm, z=0.58 mm, p>0.05). Because VIGS provides a more accurate result and reduces the required time, compared with the MVCT method, it is expected to manage the overall tomotherapy treatment process more efficiently.

• Korean Journal of Poultry Science
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• v.44 no.1
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• pp.29-39
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• 2017

This study examined the effects of adding dried blood mixed with Macsumsuk to the feed of broiler chickens. The blood had been dried at $200^{\circ}C$ in an ultra-high-temperature injection system and mixed in a 70:30 proportion of blood meal to Macsumsuk. The experiment consisted of four treatment groups of 150 chickens each. The control group received common broiler feed only, while treatment groups T1, T2, and T3 received feed supplemented with 0.5, 1.0, and 3.0% of the blood meal/Macsumsuk mixture, respectively. The diets were fed for a total of 35 days. Compared with the controls, body weight gain was improved in groups T1 (1,621 g), T2 (1,749 g), and T3 (1,739 g) (1,621-1,749 g vs. 1,448.5 g, respectively) and feed efficiency increased (p<0.01). The carcass rate in group T3 was higher by 83.26% than that in the controls (75.96 %) (p<0.01). The water holding capacity (WHC) increased in groups T1 and T2 (62.27 and 63.80% respectively) compared with controls (p<0.01). The intestine length was longer in groups T1 and T2 (53.98-55.48) than in controls (45.81) (p<0.01). Adding 0.5-1.0% of the dried blood meal Macsumsuk supplement resulted in a significant reduction in the cholesterol content (39.28~47.34 mg/100 g) compared with the controls (50.44 mg/100 g) (p<0.001); furthermore, the proportions of fatty acids including oleic (C18:1n9), ${\gamma}-linoleic$ (C18:3n6), eicosenoic (C20:1n9), and arachidonic (C20:4n6) acids were significantly increased (p<0.01). Compared with controls, the proportion of unsaturated fatty acids (UFA), mono-unsaturated fatty acids (MUFA), and proportion of UFA / SFA in group T1 was (68.66 vs. 69.35%, 51.22 vs 52.00%, and 2.19 vs. 2.26%, respectively) (p<0.05). However, the amino acid content of cystine and methionine of the treatment group (0.43~0.57%) was significantly higher than that of controls (0.38~0.46%) (p<0.05). Overall, supplementing the feed with 0.5-1.0% of the mixture of blood meal Macsumsuk improved productivity by increasing weight gain and feed efficiency, improved meat quality by increasing the water-holding capacity and levels of unsaturated fatty acids, and improved meat color.