• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.649-656
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• 2019

Flux cored arc welding (FCAW), which is used widely in many fields, such as shipyards, bridge structures, construction machinery, and plant industry, is an alternative to shielded metal arc welding (SMAW). FCAW is used largely in the welding of carbon and alloy steel because it can be welded in all poses and obtain excellent quality in the field under a range of working conditions. In this study, the mechanical properties of welded parts were analyzed after different welding of SS400 and SM490A using FCAW. The following conclusions were drawn. The tensile test results satisfied the KS standard tensile strength in the range of 400~510 N/mm2 in all welding positions. The bending test confirmed that most of the specimens did not show surface breakage or other defects during bending and exhibited sufficient toughness, even after plastic deformation. The hardness test results were lower than the standard value of 350 Hv of KS B 0893. Similar to the hardness test, were greater than the KS reference value. The macro test revealed no internal flaws, non-metallic inclusions, bubbles or impurities on the entire cross section of the weld, and there were no concerns regarding lamination.

• Nutrition Research and Practice
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• v.12 no.6
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• pp.486-493
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• 2018

BACKGROUND/OBJECTIVE: The honeysuckle berry (HB) contains ascorbic acid and phenolic components, especially anthocyanins, flavonoids, and low-molecular-weight phenolic acids. In order to examine the potential of HB as a hepatoprotective medicinal food, we evaluated the in vitro anti-oxidant and anti-inflammatory activities of Korean HB (HBK) and Chinese HB (HBC). MATERIALS/METHODS: Antioxidant and anti-inflammatory effects of the extracts were examined in HepG2 and RAW 264.7 cells, respectively. The anti-oxidant capacity was determined by DPPH, SOD, CAT, and ARE luciferase activities. The production of nitric oxide (NO) as an inflammatory marker was also evaluated. The Nrf2-mediated mRNA levels of heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase [quinone] 1 (Nqo1), and glutamate-cysteine ligase catalytic subunit (Gclc) were measured. The concentrations of HB extracts used were 3, 10, 30, 100, and $300{\mu}g/mL$. RESULTS: The radical scavenging activity of all HB extracts increased in a concentration-dependent manner (P < 0.01 or P < 0.05). SOD (P < 0.05) and CAT (P < 0.01) activities were increased by treatment with $300{\mu}g/mL$ of each HB extract, when compared to those in the control. NO production was observed in cells pretreated with 100 or $300{\mu}g/mL$ of HBC and HBK (P < 0.01). Treatment with $300{\mu}g/mL$ of HBC significantly increased Nqo1 (P < 0.01) and Gclc (P < 0.05) mRNA levels compared to those in the control. Treatment with $300{\mu}g/mL$ of HBK (P < 0.05) and HBC (P < 0.01) also significantly increased the HO-1 mRNA level compared to that in the control. CONCLUSIONS: Thus, the Korean and Chinese HBs were found to possess favorable in vitro anti-oxidant and anti-inflammatory activities. Nrf2 and its related anti-oxidant genes were associated with both anti-oxidant and anti-inflammatory activities in HB-treated cells. Further studies are needed to confirm these in vivo effects.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.841-847
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• 2018

Since global energy consumption and demand for energy have dramatically risen, a focus on environmental problems and sustainability has become more important. Clean and renewable energy sources such as offshore wind power generation have received attention among new renewable energy options as alternative energy resources. Due to maintenance and operational perspectives, offshore wind farms have been planned for installation in many coastal waters. However, development of offshore wind farms faces interference from existing maritime traffic along the planned areas. In order to safely and effectively govern marine traffic in the vicinity of wind farms and inner areas, standard criteria are suggested to allow vessels to sail the internal waters of offshore wind farm areas. Therefore, the purpose of this study is to establish allowable criteria for sailing vessels and safety zones for offshore wind farms by investigating the local regulations of various offshore wind farm cases overseas. The commended inner safety zone of wind farms is proposed to be a distance of 150 % of the rotation diameter of the wind turbine rotor and a distance of 200 m from the outer wind turbine for the outer safety zone. Besides this, the allowable criteria for sailing vessels within a wind farm is proposed to have an air draft of 14.47 m south-west wind farm sea areas for a minimum margin to avoid hull contact through evaluation of the tide and height of a wind turbine. further studies will be needed to establish vessel sailing criteria among adjacent offshore wind farms as well as vessel sailing criteria within a single offshore wind farm.

• Asian Spine Journal
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• v.12 no.6
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• pp.1060-1068
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• 2018

Study Design: Retrospective study. Purpose: Lumbar intervertebral disc degeneration is an important cause of low back pain. Overview of Literature: Spinal fusion is often reported to have a good course for adolescent idiopathic scoliosis (AIS). However, many studies have reported that adjacent segment degeneration is accelerated after lumbar spinal fusion. Radiography is a simple method used to evaluate the orientation of the vertebral column. magnetic resonance imaging (MRI) is the method most often used to specifically evaluate intervertebral disc degeneration. The Pfirrmann classification is a well-known method used to evaluate degenerative lumbar disease. After spinal fusion, an increase in stress, excess mobility, increased intra-disc pressure, and posterior displacement of the axis of motion have been observed in the adjacent segments. Methods: we retrospectively secured and analyzed the data of 15 patients (four boys and 11 girls) with AIS who underwent a spinal fusion surgery. We studied the full-length view of the spine (anterior-posterior and lateral) from the X-ray and MRI obtained from all patients before surgery. Postoperatively, another full-length spine X-ray and lumbosacral MRI were obtained from all participants. Then, pelvic tilt, sacral slope, curve correction, and fused and free segments before and after surgery were calculated based on X-ray studies. MRI images were used to estimate the degree to which intervertebral discs were degenerated using Pfirrmann grading system. Pfirrmann grade before and after surgery were compared with Wilcoxon signed rank test. While analyzing the contribution of potential risk factors for the post-spinal fusion Pfirrmann grade of disc degeneration, we used generalized linear models with robust standard error estimates to account for intraclass correlation that may have been present between discs of the same patient. Results: The mean age of the participant was 14 years, and the mean curvature before and after surgery were 67.8 and 23.8, respectively (p<0.05). During the median follow-up of 5 years, the mean degree of the disc degeneration significantly increased in all patients after surgery (p<0.05) with a Pfirrmann grade of 1 and 2.8 in the L2-L3 before and after surgery, respectively. The corresponding figures at L3-L4, L4-L5, and L5-S1 levels were 1.28 and 2.43, 1.07 and 2.35, and 1 and 2.33, respectively. The lower was the number of free discs below the fusion level, the higher was the Pfirrmann grade of degeneration (p<0.001). Conversely, the higher was the number of the discs fused together, the higher was the Pfirrmann grade. Conclusions: we observed that the disc degeneration aggravated after spinal fusion for scoliosis. While the degree of degeneration as measured by Pfirrmann grade was directly correlated by the number of fused segments, it was negatively correlated with the number of discs that remained free below the lowermost level of the fusion.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.102-110
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• 2019

The shipbuilding and offshore plant industry of Korea is important and leads Korea's economic growth, designated as the 1st to 4th export items in Korea in terms of export contribution over the period from 2011 to 2015. This study proposes ways to improve the national competitiveness of Korean shipyards in the global offshore drilling market by reviewing a business model for providing an integrated offshore drilling commissioning service in Korea. This commissioning service model, which was attempted in 2014, was reviewed, and a new proposed business model for overcoming the limitations of the previous model and activating further business was evaluated. As a result of an economic evaluation, it was found that a 150-meter water depth model is economically more effective. As the number of integrated commissions increased from 2 to 5 times per year, NPV, IRR and B/C ratios increased and the fee per use decreased. Therefore, for offshore drilling facilities constructed and delivered in Korea, it will be necessary to encourage integrated offshore commissioning.

• Management & Information Systems Review
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• v.38 no.3
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• pp.151-170
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• 2019

This study deals with the rent-seeking behavior that exist in cultural voucher from the viewpoint of culture and arts management. Art organizations open to consumers, producers and governments of the arts are dependent on the internal and external influence of an open system. Researcher has found rent-seeking in the course of introducing policies and legalization of the cultural voucher business which has been promoted in the direction of democratization of culture or cultural democracy. Cultural voucher business is a legal term. Although the government has increased the budget or tried to change the policies of the cultural voucher business, the implementation of the cultural voucher business has been opposed to the diversity of consumption and equity as the consumption of genre and the concentration of the capital region have increased. These results were structurally related to the process of legalization and rent-seeking behavior in bureaucracy. This study reaffirms that the efficient operation standard of the cultural voucher business is a balance between the choice of the beneficiary, the competition of the supplier, and access to the cultural voucher. And the theory of rent-seeking was applied as a criterion to analyze this balance. Thus, it is suggested that the criteria of evaluation and improvement to check the conservativeness of bureaucrats are needed to establish a legal system applied to the purpose of 'cultural democracy' and 'democratization of culture' ideology and to guarantee individual creativity and autonomy.

• Journal of Radiation Protection and Research
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• v.45 no.4
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• pp.178-186
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• 2020

Background: Reactor pressure vessel (RV) with internals (RVI) are activated structures by neutron irradiation and volume contaminated wastes. Thus, to develop safe and optimized disposal plan for them at a disposal site, it is important to perform exact activation calculation and evaluate the dose rate on the surface of casks which contain cut-off pieces. Materials and Methods: RV and RVI are subjected to neutron activation calculation via Monte Carlo methodology with MCNP6 and ORIGEN-S program-neutron flux, isotopic specific activity, and gamma spectrum calculation on each component of RV and RVI, and dose rate evaluation with MCNP6. Results and Discussion: Through neutron activation analysis, dose rate is evaluated for the casks containing cut-off pieces produced from decommissioned RV and RVI. For RV cut-off ones, the highest value of dose rate on the surface of cask is 6.97 × 10-1 mSv/hr and 2 m from it is 3.03 × 10-2 mSv/hr. For RVI cut-off ones, on the surface of it is 0.166 × 10-1 mSv/hr and 2 m from it is 1.04 × 10-1 mSv/hr. Dose rates for various RV and RVI cut-off pieces distributed lower than the limit except the one of 2 m from the cask surface of RVI. It needs to adjust contents in cask which carries highly radioactive components in order to decrease thickness of cask. Conclusion: Two types of casks are considered in this paper: box type for very-low-level waste (VLLW) as well as low-level waste (LLW) and cylinder type for intermediate-level waste (ILW). The results will contribute to the development of optimal loading plans for RV and RVI cut-off pieces during the decommissioning of nuclear power plant that can be used to prepare radioactive waste disposal plans for the different types of wastes-ILW, LLW, and VLLW.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.15-25
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• 2022

In this study, the efficiency of treatment of moisture and organic matter in food waste was analyzed according to the air blast volume and preheating using the bio-drying method. Te mount of air blast volume and preheating were determined by the evaluation of temperature and CO2 during food waste treatment using the bio-drying method. As a results, the increase in the air blast volume increased the moisture removal efficiency and removal rate, but, lowered the temperature inside the bio-drying by the decease in microbial activity. In order to maintain the activity of microorganisms, it was estimated that it was necessary to inject an appropriate air blast rate according th the properties of the food waste. In this study, the injection of air blast volume at 15L/min was optimal. It was evaluated that the organic matter and water removal rates according to the presence or absence of air preheating, the organic matter removal rate and water removal rate increased by 3-5% when air preheating was not performed. Also, there was no internal aggregation caused by the generation of condensate inside the bio-drying. Therefore, for effective bio-drying of food waste, it is necessary to maintain an appropriate air blast volume to maintain microbial activity, and it is considered that injection through preheating of air is required.

• Journal of the Korean GEO-environmental Society
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• v.22 no.2
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• pp.5-13
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• 2021

In this study, as the production of high-strength steel pipes due to the development of steel materials, the stability and applicability of the soil nailing method using high-strength steel pipes were evaluated. Rebars used as reinforcement in the soil nailing method are the same in order to determine the behavioral characteristics and the effect of increasing the reinforcement when replacing it with a high-strength steel pipe of a diameter, a field test were conducted to confirm the stability. As a result of the tensile test, the measured strain is smaller than the strain in the theoretical equation, so it can be seen that the behavior is similar to that of the soil nailing method using rebars. As a result of the displacement measurement, the displacement of the high-strength steel pipe is larger than that of the rebars is considered to be the effect of the internal grouting effect of the steel pipe and the decrease in the cross-sectional area. In the case of using high-strength steel pipes for the soil nailing method, it is judged that the field applicability is good by improving stability and workability through member performance and weight reduction.

• Journal of agriculture & life science
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• v.53 no.6
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• pp.45-53
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• 2019

The purpose of this study is to analyze the status of the joint forest project, which is one of the national forest management system, by using stakeholder participation, transparency of decision making, accountability of actors and stakeholders, The questionnaire survey was conducted using the 5 - point scale and the written form. As a result of the questionnaire survey, various stakeholder participation items had the highest opportunity to participate with an average of 3.3 and the lowest score with 2.3 points for establishing conflict and conflict resolution structures. Transparency was analyzed to be 3.4 points for the project disclosure, 2.7 points for information sharing and education promotion activities for local residents, 3.3 points for the detailed role of the project implementer, and 2.7 points for internal and external monitoring and evaluation of the project with various stakeholders. The results of this research, analyzed through the participatory forest management index, are deemed to be used as basic data for the establishment of a plan for the revitalization of national forest participation management.