• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.497-505
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• 2021

Due to recent underground space accidents, are a frequent occurence in Korea, the government established the basic plan for the construction of the IUGIM (Integrated Underground Geospatial Information Map) in 2015 as a measure for safety management of underground spaces. The development of IUGIM was partially completed as of 2021. The underground space management entity and related organizations are utilizing it. This study is being carried out as part of a plan to improve the usability of IUGIM, and to build a visualization system that compares real-time field data with stored data. A system, equipped with a visualization function for borehole data and 6 types of underground facilities built and managed on IUGIM; a tool capable of comparative analysis with real-time data measured in the field, is being built. The 6 types of underground facilities are water supply pipe, sewage pipe, power pipe, gas pipe, communication pipe, and heating pipe. The completed system was demonstrated at three locations in Seocho-gu, Gangnam-gu in Seoul. The field demonstration was carried out by accessing the mobile center and downloading IUGIM data, visualizing IUGIM data (surface creation, borehole information, underground facilities), and visualizing the GPR(Ground Penetrating Radar)-based data acquired at the field. As a result of the empirical results of IUGIM data and GPR-based field data, it was judged to be suitable. As a result of this study, it is judged that it can be helpful for safe construction at the excavation site.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.23-29
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• 2022

To detect harmful chemical substances in seawater, we fabricated a prototype sensor and evaluated its performance. The prototype sensor consisted of a detector, housing, and driving circuit. We built the detector by printing an Indium-Tin-Oxide (ITO) nanoparticle film on a flexible substrate, and it had two detection parts for simultaneous detection of temperature and HNS concentration. The housing connected the detector and the driving circuit and was made of Teflon material to prevent chemical reactions that may affect sensor performance. The driving circuit supplied electric power, and display measured data using a bridge circuit and an Arduino board. We evaluated the sensor performances such as response (ΔR), the limit of detection (LOD), response time, and errors to confirm the specification.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.5
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• pp.357-371
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• 2023

In cable tunnel construction using TBM, the vertical shaft is an essential structure for entrance and exit of TBM equipment and power lines. Since a shaft penetrates the ground vertically, it often encounters rock mass. Blasting or rock splitting methods, which are mainly used to the rock excavation, cause public complaints due to the noise, vibration and road occupation. Therefore, mechanical excavation using vertical shaft excavation machine are considered as an alternative to the conventional methods. However, at the current level of technology, the vertical excavation machine has limitation in its performance when applied for high strength rock with a compressive strength of more than 120 MPa. In this study, the potential utilization of waterjet technology as an excavation assistance method was investigated to improve mechanical excavation performance in the hard rock formations. Rock cutting experiments were conducted to verify the cutting performance of the abrasive waterjet. Based on the experimental result, it was found that ensuring excavation performance with respect to changing in ground conditions can be achieved by adjusting waterjet parameters such as standoff distance, traverse speed and water pressure. In addition, based on the relationship between excavation performance, uniaxial compressive strength and RQD, it was suggested that excavation performance could be improved by artificially creating joints using the abrasive waterjet. It is expected that these research results can be utilized as fundamental data for the introduction of vertical shaft excavation machines in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.127-138
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• 2023

A variety of decarbonized energy sources are being developed globally to realize carbon neutrality (Net Zero) by 2050 as a measure to address the global climate crisis. As the Korean government has also established a Renewable Energy 3020 policy and promoted energy development plans using solar or wind power, large-scale offshore development projects not present before in coastal waters, such as offshore wind farms, are being promoted. From ships' point of view, offshore facilities present obstacles to safe navigation, and with the installation of marine facilities, ship collisions or contact accidents between ships and marine facilities may occur in the narrowed water areas. In addition, there are concerns about environmental pollution and human casualties caused by marine accidents. Accordingly, we review overseas and domestic offshore wind farm development plans, analyze whether institutional devices are in place to ensure the safe passage of ships in wind farm areas, and study the safe operation of large-scale offshore wind farms and safe passage of ships along the Korean coast by comparing overseas legislative cases with domestic laws and presenting a proposal to illuminate the legal blind sectors.

• Journal of Convergence for Information Technology
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• v.12 no.3
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• pp.244-251
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• 2022

This study attempted to investigate the applicability of Geranium maculatum extract as a cosmeceutical ingredient. For this, DPPH, ABTS and FRAP assays were performed to assess radical scavenging activities. To evaluate antioxidant substances, in addition, polyphenol and flavonoid concentrations were measured. Furthermore, cytotoxicity, whitening and anti-inflammatory tests were conducted, using B16F10 and RAW 264.7 cells, and the results found the followings: In the DPPH and ABTS assays, 265.8 mg ascorbic acid/g and 168.5 mg ascorbic acid/g of antioxidant capacities were found respectively. According to the FRAP assay, 1 mg Geranium maculatum extract was same with ascorbic acid 229±9 ㎍ in terms of reducing power. In polyphenol and flavonoid concentrations, 32.989±1.610 mg/g and 11.098±0.261 mg/g were observed each. The above results show that cells survived in the test concentrations more than 80 percent, confirming the low toxicity of Geranium maculatum extract. According to whitening testing, melanin synthesis was reduced depending on concentration, and at the same time, 40.62±2.07% of melanin production inhibition was found at 100 ㎍/mL. In anti-inflammatory testing, inflammation was reduced depending on concentration, and 27.86±2.82% of inhibition of inflammation was detected simultaneously, confirming the applicability of Geranium maculatum extract as a cosmeceutical ingredient.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1593-1603
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• 2023

In deterministic and Monte Carlo transport codes, b-delayed emission is included using a group structure where all of the precursors are grouped together in 6 groups or families, but given the increase in computational power, nowadays there is no reason to keep this structure. Furthermore, there have been recent efforts to compile and evaluate all the available b-delayed neutron emission data and to measure new and improved data on individual precursors. In order to be able to perform a transient Monte Carlo simulation, data from individual precursors needs to be implemented in a transport code. This work is the first step towards the development of a tool to explore the effect of individual precursors in a fissile system. In concrete, individual precursor data is included by expanding the capabilities of the open source Monte Carlo code OpenMC. In the modified code - named Time Dependent OpenMC or OpenMC(TD)- time dependency related to β-delayed neutron emission was handled by using forced decay of precursors and combing of the particle population. The data for continuous energy neutron cross-sections was taken from JEFF-3.1.1 library. Regarding the data needed to include the individual precursors, cumulative yields were taken from JEFF-3.1.1 and delayed neutron emission probabilities and delayed neutron spectra were taken from ENDF-B/VIII.0. OpenMC(TD) was tested in a monoenergetic system, an energy dependent unmoderated system where the precursors were taken individually or in a group structure, and in a light-water moderated energy dependent system, using 6-groups, 50 and 40 individual precursors. Neutron flux as a function of time was obtained for each of the systems studied. These results show the potential of OpenMC(TD) as a tool to study the impact of individual precursor data on fissile systems, thus motivating further research to simulate more complex fissile systems.

• Journal of Life Science
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• v.34 no.5
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• pp.296-303
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• 2024

Vinegar is a fermented food product created by fermenting various sugar- and starch-containing ingredients with microorganisms. It contains a variety of organic acids, sugars, amino acids, esters, and other compounds that contribute to its unique sensory properties. Vinegar is known for its potential benefits, including aiding digestion, lowering blood sugar levels, anti-obesity effects, and antioxidant properties. It is also believed to contribute to improving alkaline body conditions. This study was conducted to develop functional dried vinegar powder from naturally fermented vinegars. Unripe apple, brown rice, and black chokeberry (aronia) were fermented using Gluconacetobacter xylinus for 90-180 days. The filtrate vinegar was spray dried with 37.46% maltodextrin, 5% glucose, 1% citric acid, and 0.04% vitamin C. Analysis of the acidity, color difference, water and soluble solid content, and heat stability of dried vinegar (DV) confirmed that spray drying is a suitable method for powder production. Moreover, the DVs exhibited excellent sensory attributes and solubility. Among the DVs, aronia-DV showed the highest 1,1-diphenyl-2-picryl hydrazyl and 2,2-azobis (3- ethylbenzothiazoline-6-sulfonate) radical scavenging activity (36.7% and 75.3%) and reducing power (0.334) at 0.5 mg/ml concentration, respectively. The nitrite scavenging activity was highest in brown unripe apple-DV, followed by aronia-DV and brown rice-DV. In the anti-thrombosis activity assay, aronia-DV showed the highest prothrombin inhibition. The brown rice-DV exhibited lipid accumulation inhibitory activity in 3T3-L1 adipocytes without cell cytotoxicity. Our results suggest the potential for commercialization of dried vinegar, highlighting its diverse benefits and applications.

• Journal of Ecology and Environment
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• v.47 no.4
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• pp.272-281
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• 2023

Ecosystem observatories are burgeoning globally in an endeavour to detect national and global scale trends in the state of biodiversity and ecosystems in an era of rapid environmental change. In this paper we highlight the additional importance of regional scale outcomes of such infrastructure, through an introduction to the Great Western Woodlands TERN (Terrestrial Ecosystem Research Network) SuperSite, and key findings from three gradient plot networks that are part of this infrastructure. The SuperSite was established in 2012 in the 160,000 km² Great Western Woodlands region, in a collaboration involving 12 organisations. This region is globally significant for its largely intact, diverse landscapes, including the world's largest Mediterranean-climate woodlands and highly diverse sandplain shrublands. The dominant woodland eucalypts are fire-sensitive, requiring hundreds of years to regrow after fire. Old-growth woodlands are highly valued by Indigenous and non-Indigenous communities, and managing impacts of climate change and the increasing extent of intense fires are key regional management challenges. Like other TERN SuperSites, the Great Western Woodlands TERN SuperSite includes a core eddy-covariance flux tower measuring exchanges of carbon, water and energy between the vegetation and atmosphere, along with additional environmental and biodiversity monitoring around the tower. The broader SuperSite incorporates three gradient plot networks. Two of these represent aridity gradients, in sandplains and woodlands, informing regional climate adaptation and biodiversity management by characterising biodiversity turnover along spatial climate gradients and acting as sentinels for ecosystem change over time. For example, the sandplains transect has demonstrated extremely high spatial turnover rates in plant species, that challenge traditional approaches to biodiversity conservation. The third gradient plot network represents a 400-year fire-age gradient in Eucalyptus salubris woodlands. It has enabled characterisation of post-fire recovery of vegetation, birds and invertebrates over multi-century timeframes, and provided tools that are directly informing management to reduce stand-replacing fires in eucalypt woodlands. By building regional partnerships and applying globally or nationally consistent methodologies to regional scale questions, ecological observatories have the power not only to detect national and global scale trends in biodiversity and ecosystems, but to directly inform environmental decisions that are critical at regional scales.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.5
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• pp.551-561
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• 2024

Underground utility tunnels are spaces densely packed with various infrastructure facilities, such as power, telecommunications, and water supply and drainage systems, making internal environment management crucial. An investigation into accident cases and on-site demands in these tunnels revealed that while fires and floods are the most common types of incidents, the demand for real-time condensation prevention and response is frequent according to on-site managers. Condensation occurs due to the difference in humidity and temperature between the inside and outside of the tunnel. Frequent or prolonged condensation can lead to metal pipe corrosion, electrical failures, and reduced equipment lifespan. Therefore, this study developed a control algorithm and monitoring system to prevent condensation in underground utility tunnels. The proposed control algorithm estimates the likelihood of condensation in real-time based on the measured temperature and humidity and suggests appropriate responses for each stage to the managers. Finally, a practical condensation prevention monitoring system was built based on the developed algorithm, verifying the feasibility and applicability of this technology in the field.

• Journal of the Korean Geosynthetics Society
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• v.14 no.4
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• pp.59-77
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• 2015

In order to meet the new requirements for landfill materials, this study planned a study to apply mixed soil of mixing bottom ash and coastal dredged soil to the dredged ground. Coal ash generated from thermal power plant is divided into fly ash and bottom ash. In the case of fly ash, many studies have been conducted because small particles causes permeability coefficient to be small during recycling so no problem has been raised in the environmental area but the utilization of bottom ash has been limited because environmental problems have been raised during recycling due to its larger particle size and greater permeability coefficient. According to recently published studies, however, the results of the study that conducted the water analysis of leachate generated in the ground improvement section using bottom ash showed that heavy metal contamination levels were found to be within the reference value and no significant environmental problems were found so utilization of bottom ash is evaluated to increase significantly in the future. This bottom ash has the particle size of sand and only transportation costs need to be considered when providing materials because the majority has been disposed and it is judged as the most suitable material in dredging landfill in the economic aspect because most thermal power plants are located in the coast and transportation costs can be reduced by ship. Also, research on mixed soil that can maximize the effect of the construction period and construction cost savings than dredged soil is determined as needed because the demand for coastal dredging reclamation is increasing such as Saemangeum project etc. Therefore, we studied self-weight consolidation characteristics depending on sample processing and mixing method of mixed soil by carrying out interior self-weight consolidation experiments on mixed soil of mixing bottom ash and Kaolinite according to the new development needs of recent coastal reclaimed ground and these result findings are expected to be used as basic data when applying the large coastal dredged ground in the future.