• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.92-111
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• 2011

This study focus on the restoration stone selection of break-out part based on material characteristics analysis and the conservational safety diagnosis using various nondestructive techniques for Jungdong and Banjukdong Stone Auariums. As a result, the original rocks of the stone aquariums body are porphyritic granodiorite with magnetite-series having igneous lineation, microcline phenocryst, veinlet and basic xenolith. As a result of the provenance presumption of the host rock, a rock around Gamgokri area in Nonsan City was identified the genetically same rock. Therefore, the rock is appropriate for restoration materials of the break-out part. The deterioration assessment showed that the stone aquariums were highly serious scaling, scale off and blackening. Particularly, the front face of Banjukdong stone aquarium needs reinforcement of structural crack (760mm) caused from igneous lineation of biotite. Blackening contaminants on the stone aquariums surface occurred by combining iron oxide, manganese oxide and clay mineral. Also, major factors of efflorescence contaminants were identified as calcite (Jungdong stone aquariums) and gypsum (Banjukdong stone aquariums). The physical characteristics of stone aquariums appeared that the original and new stone is third (moderately weathered) and second grade (slightly weathered), respectively. This study sets up an integrated conservation system from material analysis to restoration stone selection and conservational safety diagnosis of Jungdong and Banjukdong stone aquariums.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.132-141
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• 2019

The necessity of transmitting video data over a narrow-bandwidth exists steadily despite that video service over broadband is common. In this paper, we propose a scalable video coding framework for low-resolution video transmission over a very narrow-bandwidth network by super-resolution of decoded frames of a base layer using a convolutional neural network based super resolution technique to improve the coding efficiency by using it as a prediction for the enhancement layer. In contrast to the conventional scalable high efficiency video coding (SHVC) standard, in which upscaling is performed with a fixed filter, we propose a scalable video coding framework that replaces the existing fixed up-scaling filter by using the trained convolutional neural network for super-resolution. For this, we proposed a neural network structure with skip connection and residual learning technique and trained it according to the application scenario of the video coding framework. For the application scenario where a video whose resolution is $352{\times}288$ and frame rate is 8fps is encoded at 110kbps, the quality of the proposed scalable video coding framework is higher than that of the SHVC framework.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1243-1244
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• 2022

In recent years, the growing interest in off-site construction has led to factories scaling up their manufacturing and production processes in the construction sector. Consequently, continuous large-scale site monitoring in low-variability environments, such as prefabricated components production plants (precast concrete production), has gained increasing importance. Although many studies on computer vision-based site monitoring have been conducted, challenges for deploying this technology for large-scale field applications still remain. One of the issues is collecting and transmitting vast amounts of video data. Continuous site monitoring systems are based on real-time video data collection and analysis, which requires excessive computational resources and network traffic. In addition, it is difficult to integrate various object information with different sizes and scales into a single scene. Various sizes and types of objects (e.g., workers, heavy equipment, and materials) exist in a plant production environment, and these objects should be detected simultaneously for effective site monitoring. However, with the existing object detection algorithms, it is difficult to simultaneously detect objects with significant differences in size because collecting and training massive amounts of object image data with various scales is necessary. This study thus developed a large-scale site monitoring system using edge computing and a small-object detection system to solve these problems. Edge computing is a distributed information technology architecture wherein the image or video data is processed near the originating source, not on a centralized server or cloud. By inferring information from the AI computing module equipped with CCTVs and communicating only the processed information with the server, it is possible to reduce excessive network traffic. Small-object detection is an innovative method to detect different-sized objects by cropping the raw image and setting the appropriate number of rows and columns for image splitting based on the target object size. This enables the detection of small objects from cropped and magnified images. The detected small objects can then be expressed in the original image. In the inference process, this study used the YOLO-v5 algorithm, known for its fast processing speed and widely used for real-time object detection. This method could effectively detect large and even small objects that were difficult to detect with the existing object detection algorithms. When the large-scale site monitoring system was tested, it performed well in detecting small objects, such as workers in a large-scale view of construction sites, which were inaccurately detected by the existing algorithms. Our next goal is to incorporate various safety monitoring and risk analysis algorithms into this system, such as collision risk estimation, based on the time-to-collision concept, enabling the optimization of safety routes by accumulating workers' paths and inferring the risky areas based on workers' trajectory patterns. Through such developments, this continuous large-scale site monitoring system can guide a construction plant's safety management system more effectively.

• Journal of the Korean Society of Radiology
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• v.81 no.6
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• pp.1348-1363
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• 2020

The newly revised 2018 Organ Injury Scale (OIS) has a similar format to the previous American Association for Surgery and Trauma (AAST) Emergency General Surgery Grading System, dividing the criteria for grading solid organ damage into three groups; imaging, operation, and pathology. The most significant alteration in the OIS system 2018 revision is the incorporation of multidetector CT (MDCT) findings of vascular injury including pseudoaneurysm and arteriovenous fistula. Similar to the previous OIS, the highest of the three criteria is assigned the final grade. In addition, if multiple grade I or II injuries are present, one grade is advanced for multiple injuries up to grade III. This pictorial essay demonstrates the MDCT findings of solid organ injury grades based on the 2018 OIS system.

• Journal of the Mineralogical Society of Korea
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• v.21 no.4
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• pp.341-347
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• 2008

The feasibility of commercializing the hydrothermal synthesis of Na-A type zeolite from siliceous mudstone has been conducted using a 50-liter bench-scale autoclave and the application of the zeolite as an environmental remediation agent. Siliceous mudstone, which is widely distributed around the Pohang area, was adopted as a precursor. The siliceous mudstone is favorable for the synthesis of zeolite because it contains 70.7% $SiO_2$ and 10.0% $Al_2O_3$, which are major ingredient of zeolite formation. The synthesis of zeolite was carried out under the following conditions that had been obtained from the previous laboratory-scale tests: 10hr reaction time, $80^{\circ}C$ reaction temperature, $Na_2O/SiO_2$ ratio = 0.6, $SiO_2/Al_2O_3$ ratio = 2.0 and $H_2O/Na_2O$ ratio= 98.6. The crystallinity and morphology of the zeolite formed were similar to those obtained from the laboratory-scale tests. The recovery and cation exchange ion capacity were 95% and 215 cmol/kg, respectively, which are slightly higher than those obtained in laboratory scale tests. To examine the feasibility of the zeolite as an environmental remediation agent, experiments for heavy metal adsorption to zeolite were conducted. Its removal efficiencies of heavy metals in simulated waste solutions decreased in the following sequences: Pb > Cd > Cu = Zn > Mn. In a solution of 1500 mg/L total impurity metals, the removal efficiencies for these impurity metals were near completion (> 99%) except for Mn whose efficiency was 98%. Therefore, the synthetic Na-A type zeolite was proven to be a strong absorbent effective for removing heavy metals.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.277-287
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• 2007

To understand the effects of the powdered manganese nodule and sea bottom sediment pumped up with nodules on the mining process, the shattering ratio of manganese nodule and their physical properties are analyzed. The self shattering ratio and crushing shattering ratio are about 27% and about 3%, respectively. Then total shattering ratio is about 30%. The initial turbidity of the powdered manganese nodule and the bottom sediment show high, i.e., about 3,100 and 1,850 respectively. But their turbidities decrease rapidly with time. After 1 hour, turbidity of the powdered manganese nodule drops to about 1,570 and that of the bottom sediment to 1,310. The turbidity of Na-bentonite changes from 820 to 730 after 1 h and to 700 after 2 h. The viscosity of powdered manganese nodule is $1.4{\sim}1.5cP$, and the viscosity of bottom sediment is less than 1 cP. The viscosity fo Na-bentonite is initially 37.2 and increase with time to 86.4 cP after 30 min. The high initial turbidity of powdered manganese nodule is due to dark color of the powder. The high specific gravity makes rapid precipitation and then decreases the turbidity rapidly. The bottom sediment shows high initial turbidity because of easy suspension with very fine particle size. But it cannot be hydrated and formed gel in suspension, then it is easily precipitated. However Na-bentonite is hydrated to the expended state and makes gel state, then it shows high turbidity and high viscosity. These physical properties of the powdered manganese nodule suggest that the powder of manganese nodule should not make scaling inside of lifting pipe or pump. And the bottom sediment lifted up with manganese nodule should not play the role of drilling mud shch as Na-bentonite.

• Journal of the Korean Society of Groundwater Environment
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• v.7 no.3
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• pp.103-115
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• 2000

The formation of brown-colored precipitates is one of the serious problems frequently encountered in the development and supply of groundwater in Korea, because by it the water exceeds the drinking water standard in terms of color. taste. turbidity and dissolved iron concentration and of often results in scaling problem within the water supplying system. In groundwaters from the Pajoo area, brown precipitates are typically formed in a few hours after pumping-out. In this paper we examine the process of the brown precipitates' formation using the equilibrium thermodynamic and kinetic approaches, in order to understand the origin and geochemical pathway of the generation of turbidity in groundwater. The results of this study are used to suggest not only the proper pumping technique to minimize the formation of precipitates but also the optimal design of water treatment methods to improve the water quality. The bed-rock groundwater in the Pajoo area belongs to the Ca-$HCO_3$type that was evolved through water/rock (gneiss) interaction. Based on SEM-EDS and XRD analyses, the precipitates are identified as an amorphous, Fe-bearing oxides or hydroxides. By the use of multi-step filtration with pore sizes of 6, 4, 1, 0.45 and 0.2 $\mu\textrm{m}$, the precipitates mostly fall in the colloidal size (1 to 0.45 $\mu\textrm{m}$) but are concentrated (about 81%) in the range of 1 to 6 $\mu\textrm{m}$in teams of mass (weight) distribution. Large amounts of dissolved iron were possibly originated from dissolution of clinochlore in cataclasite which contains high amounts of Fe (up to 3 wt.%). The calculation of saturation index (using a computer code PHREEQC), as well as the examination of pH-Eh stability relations, also indicate that the final precipitates are Fe-oxy-hydroxide that is formed by the change of water chemistry (mainly, oxidation) due to the exposure to oxygen during the pumping-out of Fe(II)-bearing, reduced groundwater. After pumping-out, the groundwater shows the progressive decreases of pH, DO and alkalinity with elapsed time. However, turbidity increases and then decreases with time. The decrease of dissolved Fe concentration as a function of elapsed time after pumping-out is expressed as a regression equation Fe(II)=10.l exp(-0.0009t). The oxidation reaction due to the influx of free oxygen during the pumping and storage of groundwater results in the formation of brown precipitates, which is dependent on time, $Po_2$and pH. In order to obtain drinkable water quality, therefore, the precipitates should be removed by filtering after the stepwise storage and aeration in tanks with sufficient volume for sufficient time. Particle size distribution data also suggest that step-wise filtration would be cost-effective. To minimize the scaling within wells, the continued (if possible) pumping within the optimum pumping rate is recommended because this technique will be most effective for minimizing the mixing between deep Fe(II)-rich water and shallow $O_2$-rich water. The simultaneous pumping of shallow $O_2$-rich water in different wells is also recommended.

• Korean Journal of Environmental Biology
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• v.28 no.4
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• pp.179-187
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• 2010

The Theory of Island Biogeography describes that the number of species on an island affected by island area and distance from the mainland. This study was performed to compare and analyze the community structure of the macro-invertebrates in three isolated islands, around Korean waters in terms of the Theory of Island Biogeography. Macrobenthic animals were collected using a modified underwater quadrat in August 2009. A total of 104 macrobenthic species were sampled with a mean density of 399 individuals $m^{-2}$ and biomass of 1,506.70 g $m^{-2}$. Based on the abundance and biomass data, there were 10 dominant species accounting for approximately 67.17% of total individuals. The highest densities were found in the amphipoda Amphipoda spp., the bivalvia Modiolus agripetus and Mytilus coruscus, the Sipunculida Phascolosoma scolops and the polychaeta Syllidae unid.. On the contrary, the top ten species made up 95.66% of the total biomass while the three most abundant, the bivalves M. coruscus, Streostria circumpicta and M. agripetus. The conventional multi-variate statistics (cluster analysis and non-metric multi-dimensional scaling) applied to assess spatial variation in macrobenthic assemblages. Cluster analysis and nMDS ordination analysis based on the Bray-Curtis similarity identified 2 station groups. The group 1 was consisted with Gageodo (except for lower station at Transect 2) and Dokdo station and was numerically dominated by the polychaetes Eunice antennata and Syllidae unid., the cirripedia Megabalanus rosa and the bivalvia M. coruscus. However, group 2 was associated with Sohwado station and was characterized by high abundance of the anomura Petrolisthes japonicus, the gastropoda Lirularia pygmaea and the brachiopoda Coptothyris grayi. In conclusion, these results suggested that the species diversity and community structure of macrobenthos in three isolated island seemed slightly related to island area and distance from the mainland.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.1
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• pp.65-74
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• 2016

This study mainly focuses on urban regeneration project as a countermeasure to resolve climate change issues by analyzing the carbon-reduction effect of Jeonju test-bed cases. First, an urban regeneration project is designed for city, Jeonju by analyzing its environmental problems and potential improvement. Then, carbon emission and reduction amounts are evaluated for different businesses and scenarios. Carbon emission sources are classified according to a standard suggested by IPCC, and the emissions are calculated by various standard methods. The result shows that carbon emission amount in Jeonju test-bed is 102,149 tCO2eq. The fact that 70% of the emission from energy sector originates from buildings implies that urban regeneration projects can concentrate on building portions to effectively reduce carbon emission. It is also projected carbon emission will decrease by 3,826tCo2eq in 2020 compared to 2011, reduction mainly based on overall population and industry shrinkage. When urban regeneration projects are applied to 5 urban sectors (urban environment, land use, green transportation, low carbon energy, and green buildings) total of 10,628tCO2eq is reduced and 4,857tCO2 (=15.47%) when only applied to the green building sector. Moreover, different carbon reduction scenarios are set up to meet each goal of different sectors. The result shows that scenario A, B, and C each has 5%, 11%, and 15% of carbon reduction, respectively. It is recommended to apply scenario B to achieve 11% reduction goal in a long term. Therefore, this research can be a valuable guideline for planning future urban regeneration projects and relative policies by analyzing the present urban issues and suggesting improvement directions.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.435-441
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• 1998

Optimal conditions for the production of natural color, betacyanin were investigated by varying light intensity, C/N ratio, concentrations of phosphate and kinds of elicitors. Batch cultivation was employed to characterize cell growth and betacyanin production of 32 days. The maximum specific growth rate, ${\mu}$$\sub$max/, was 0.3 (1/day) for batch cultivation. The maximum specific production rate, q$\^$max/$\sub$p/, was enhanced 0.11 (mg/g-cell/day) at 3 klux. A light intensity of 3 klux was shown to the best for both cell growth and betacyanin production. The maximum specific production rate was 0.125 (mg/g-cell/day) at 0.242 (1/day), the maximum specific growth rate. The dependence of specific growth rate on the light lintensity is fit to the photoinhibition model. The correlation between ${\mu}$ and q$\sub$p/ showed that the product formation parameters, ${\alpha}$ and ${\beta}$$\sub$p/ were 0.3756 (mg/cell) and 0.001 (mg/g-cell/day), respectively. The betacyanin production was partially cell growth related process, which is different from the production of a typical product in plant cell cultures. In C/N ratio experiment, high carbon concentration, 42.1 (w/w) improved cell growth rate while lower concentration, 31.6 (w/w) increased the betacyanin production rate. The ${\mu}$$\sub$max/ and q$\^$max/$\sub$p/ were 0.26 (1/day) and 0.075 (mg/g-cell/day), respectively. Beta vulgaris L. cells under 1.25 mM phosphate concentration produced 10.15 mg/L betacyanin with 13.46 (g-dry wt./L) of maximum cell density. The production of betacyanin was elongated by adding 0.1 ${\mu}$M of kinetin. This also increased the cell growth. Optimum culture conditions of light intensity, C/N, phosphate concentration were obtained as 5.5 klux, 27 (w/w), 1.25 mM, respectively by the response surface methodology. The maximum cell density, X$\sub$max/, and maximum production, P$\sub$max/, in optimized conditions were 16 (g-dry wt./L), 12.5 (mg/L) which were higher than 8 (g-dry wt./L), 4.48 (mg/L) in normal conditions. The ${\mu}$$\sub$max/ and q$\^$max/$\sub$p/ were 0.376 (1/day) and 0.134 (mg/g-cell/day) at the optimal condition. The overall results may be useful in scaling up hairy root cell culture system for commercial production of betacyanin.