• International conference on construction engineering and project management
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• 2022.06a
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• pp.436-442
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• 2022

Hurricanes and tornadoes are the most destructive natural disasters in some central and southern states. Thus, storm shelters, which can provide emergency protections for low-rise building residents, are becoming popular nowadays. Both FEMA and ICC have published a series of manuals on storm shelter design. However, the authors found that the materials for related products in the market are heavyweight and hard to deliver and install; renovations are necessary. The authors' previous studies found that lightweight and high-performance composite materials can withstand extreme wind pressure, but some building codes are designated in wind-borne debris areas. In these areas, wind debris can reach greater than 100 mph speed. In addition, the impact damage on the composite materials is an increasing safety issue in many engineering fields; some can cause catastrophic results. Therefore, studying composite structures subjected to wind debris impact is essential. The finite element models are set up using the software Abaqus 2.0 to conduct the simulations to observe the impact resistance behavior of the carbon fiber composite sandwich panels. The selected wood debris models meet the FEMA requirements. The outcome of this study is then employed in future lab tests and compared with other material models.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.1039-1049
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• 2023

Atopic dermatitis (AD) is a chronic inflammatory disease caused by immune dysregulation. Meanwhile, the supernatant of lactic acid bacteria (SL) was recently reported to have anti-inflammatory effects. In addition, HaCaT keratinocytes stimulated by tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) are widely used for studying AD-like responses. In this study, we evaluated the anti-inflammatory effects of SL from lactic acid bacteria (LAB) on TNF-α/IFN-γ-induced HaCaT keratinocytes, and then we investigated the strains' probiotic properties. SL was noncytotoxic and regulated chemokines (macrophage-derived chemokine (MDC) and thymus and activation-regulated chemokine (TARC)) and cytokines (interleukin (IL)-4, IL-5, IL-25, and IL-33) in TNF-α/IFN-γ-induced HaCaT keratinocytes. SL from Lacticaseibacillus rhamnosus MG4644, Lacticaseibacillus paracasei MG4693, and Lactococcus lactis MG5474 decreased the phosphorylation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK). Furthermore, the safety of the three strains was demonstrated via hemolysis, bile salt hydrolase (BSH) activity, and toxicity tests, and the stability was confirmed under simulated gastrointestinal conditions. Therefore, L. rhamnosus MG4644, L. paracasei MG4693, and Lc. lactis MG5474 have potential applications in functional food as they are stable and safe for intestinal epithelial cells and could improve atopic inflammation.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.4
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• pp.247-253
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• 2023

Revolutionary advancements, such as the reduction in DNA sequencing costs and genome editing, have transformed biotechnology, fostering progress in manipulating biomolecules, engineering cells, and computational biology. Agriculture and food production have significantly benefited from tools like high-throughput microarrays, accelerating the selection of desired traits. Genetic engineering, especially utilizing genome editing, facilitates precise alterations in plants and animals, harnessing microbiomes and fostering lab-grown meat production to alleviate environmental pressures. The emergence of new biotechnologies, notably genome editing, underscores the necessity for regulatory frameworks governing LM (living modified) organisms. Global regulations overseeing genetically engineered or genome-edited (GE) organisms, encompassing animals, exhibit considerable diversity. Nonetheless, prevailing international regulatory trends typically exclude genomeedited plants and animals, employing novel biotechnological techniques, from GMO/ LMO classification if they lack foreign genes and originate through natural mutations or traditional breeding programs. This comprehensive review scrutinizes ongoing risk and safety assessment cases, such as genome-edited beef cattle and fish in the USA and Japan. Furthermore, it investigates the limitations of existing regulations related to genome editing in Korea and evaluates newly proposed legislation, offering insights into the future trajectory of regulatory frameworks.

• Smart Structures and Systems
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• v.33 no.3
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• pp.227-241
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• 2024

Safety and structural integrity of civil structures, like bridges and buildings, can be substantially enhanced by employing appropriate structural health monitoring (SHM) techniques for timely diagnosis of incipient damages. The information gathered from health monitoring of important infrastructure helps in making informed decisions on their maintenance. This ensures smooth, uninterrupted operation of the civil infrastructure and also cuts down the overall maintenance cost. With an early warning system, SHM can protect human life during major structural failures. A real-time online damage localization technique is proposed using only the vibration measurements in this paper. The concept of the 'Degree of Scatter' (DoS) of the vibration measurements is used to generate a spatial profile, and fractal dimension theory is used for damage detection and localization in the proposed two-phase algorithm. Further, it ensures robustness against environmental and operational variability (EoV). The proposed method works only with output-only responses and does not require correlated finite element models. Investigations are carried out to test the presented algorithm, using the synthetic data generated from a simply supported beam, a 25-storey shear building model, and also experimental data obtained from the lab-level experiments on a steel I-beam and a ten-storey framed structure. The investigations suggest that the proposed damage localization algorithm is capable of isolating the influence of the confounding factors associated with EoV while detecting and localizing damage even with noisy measurements.

• Transactions of Materials Processing
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• v.33 no.5
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• pp.309-314
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• 2024

Supersonic aircraft and missiles often encounter damage issues due to high-speed collisions with small objects such as ice particles and water droplets. This can significantly impact the safety and performance of these vehicles, making the assessment and development of collision testing crucial. Existing collision testing methods have relied on equipment such as gas guns, which utilize high pressure. However, most accelerators for projectiles are large-scale devices designed for weaponry and high-pressure gases, rendering them inaccessible and unsuitable for laboratory use. Therefore, there is a need for research into easily accessible and economically efficient testing devices at the laboratory level. An impact tester can launch a projectile with a velocity of 100 m/s using low-pressure compressed air at approximately 10 bar. The velocity of the impact tester projectile is determined by the pressure within the chamber, friction, and the length of the barrel. In this study, computational fluid dynamics was utilized to define friction coefficients that match experimental results based on projectile weight, enabling accurate prediction of velocity. The resulting data provides practical and effective insights for the design of impact testers, utilizing the defined friction coefficients to understand and predict complex physical phenomena.

• Journal of Food Hygiene and Safety
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• v.35 no.6
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• pp.618-629
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• 2020

The purpose of this study was to optimize the fermentation condition of black bean by lactic acid bacteria (LAB) and to evaluate the quality characteristics of fermented black bean. Lactobacillus plantarum SU22 isolated from kimchi was selected as a starter for the fermentation of black bean because the strain exhibited strong antimicrobial activity against pathogenic bacteria and did not produce biogenic amines or a carcinogenic enzyme, β-glucuronidase. Fermentation was performed with broth containing puffed black bean (PBB) inoculated with 1% (v/v) of L. plantarum SU22 at 37℃ for 48h. The viable cell count of LAB was over 9 Log CFU/mL in PBB (20%) broth fermented with L. plantarum SU22. Fermentation of alcalase-treated PBB (20%) broth with L. plantarum SU22 was found to be the optimal condition, increasing viable cell count of LAB up to 10.30 Log CFU/mL. Under the optimal condition, the total polyphenol content (94.02 mg GAE/g) and DPPH radical scavenging activity (92.50%) were significantly increased, compared to non-fermented control (87.74 mg GAE/g, 83.14%).

• Journal of Korean Home Economics Education Association
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• v.33 no.2
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• pp.135-152
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• 2021

The purpose of this study was to examine the effectiveness of the curriculum implementation of 「Food Safety and Health」, a Home Economics elective course, for high school students. Accordingly, several units of the 「Food Safety and Health」curriculum were piloted in six high schools in Chungbuk, Gyeonggi, Daejeon, and Sejong, and 1,199 questionnaires collected from students who participated in the classes were analyzed. The results are as follows. The 「Food Safety and Health」class had a significant effect on improving the total score of 'food safety and health' knowledge of high school students and scores for sub-dimensional area. Compared to the pre-test, the overall rate of correct answers for the post-test has increased by 7.99%p, and schools that implemented the relevant unit class relatively more had higher improvement scores. In addition, the 「Food Safety and Health」class has positively changed the eating behavior of high school students, and had a significant effect on having a habit of eating a variety of foods evenly. High school students who participated in the 「Food Safety and Health」class evaluated their classes very positively (4.27 out of 5 points), and responded that the content of the class was interesting, easy to understand, and helpful for their diet in daily life. According to the responses to the open-ended questions, students responded that the class was helpful in acquiring food-related knowledge in their real lives, while there were so many limitations for experiencing lab class and group activities due to COVID 19. In preparation for the high school credit system, this study is meaningful that it has expanded the elective courses in home economics area, as well as the right to choose subjects for high school students.

• Science of Emotion and Sensibility
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• v.10 no.3
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• pp.331-342
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• 2007

This study focused on developing MP3 smart clothing products and usability evaluation. MP3 smart clothing which was developed in this study contains e-textile keypad and a kit. The kit consists of MP3 Player, remote controller module and ear phone, and are easy to assemble and dismantle. And usability evaluation about MP3 smart Clothing which was developed in this study contains e-textile keypad and a kit. For making the MP3 Smart clothing, e-textile signal line and keypad was developed and a metal connection ring also was manufactured to adhere closely e-textile signal line to keypad. The last products are two kinds of MP3 smart clothing, jacket style of MP3-YSJ(Yonsei Smart Jacket) and safari style of MP3-YSS(Yonsei Smart Safari). Then usability evaluation conducted two times about MP3 smart clothing developed. Usability evaluation is classified by a module evaluation and an item evaluation. The module evaluation measured external appearance, material, a music controller, an ear phone(or a mini speaker) and connector. The item evaluation measured social acceptance, feeling of wearing, utility, easiness of maintenance and safety. The module evaluation described totally positive results in the first usability evaluation about MP3-YSJ 1.0 and MP3-YSS 1.0. The item evaluation shows a lower score in the social acceptance, especially the easiness of connector maintenance and the social acceptance of music-controller in MP3-YSJ 1.0 and MP3-YSS 1.0. The second usability evaluation conducted with improved products by the first usability test results. Results from second item evaluation indicated needs to improve the easiness of connector & music-controller maintenance and the social acceptance of music-controller in MP3-YSJ 2.0. In MP3-YSS 2.0, the easiness of material management and the social acceptance of music controller & connector needed to improvement. In particular, users felt inconvenience in the social acceptance because of e-textile keypad arrangement. To outweigh this disadvantage, further study is needed about keypad interface of the music controller.

• Journal of the Korean GEO-environmental Society
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• v.18 no.4
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• pp.23-29
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• 2017

As the Enforcement Ordinance of Environmental Policy Act was revised in 2013, Total Organic Carbon (TOC) was added as an indicative parameter for organic matter in Water and Aquatic Ecosystem Environmental Criteria. Under these imminent circumstances, a regulatory standard is needed to achieve the proposed TOC limitation control water quality from the STP (Sewage Treatment Plant). In this study, a electrolysis utilizing the electrochemical reaction was investigated in lab-scale experiments for the treatment of TOC in sewage effluent. TOC reduction by a electrolysis was investigated response surface methodology using the Box-Begnken methods were applied to the experimental results. A central composite design was used to investigate the effects of the independent variables of electrode space ($x_1$), current density ($x_2$) and electrolyte concentration ($x_3$) on the dependent variables removal efficiency of TOC (y). The optimal conditions for electrolysis were determined: electrode space, current density and electrolyte concentration were 50 mm, $10.3mA/cm^2$ and 0.1M, respectively. Statistical results showed the order of significance of the independent variables to be electrode space > current density > electrolyte concentration.

• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.2 s.21
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• pp.7-15
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• 2004

To maintain and improve seafarers oral health, I investigated and analyzed the oral health status of seafarers: who are safety training at Korea Institute of Maritime and Fisheries Technology located in Busan. The results of the investigation and analysis are as follows: Two times of brushing teeth a day occupied $51.0\%$ the largest percentage, mixed brushing method was the highest as $39.0\%$, $64.2\% of respondents have recieved teeth scaling. Two or three of times snack intake per day occupied $62.6\%$ the largest percentage. Based on the objects' answer on oral status, the persons answered that my oral status is 'good' $25.9\%$ 'bad' $38.3\%$ occupied The persons with a decayed tooth occupied $78.1\%$ and as for the subjective symptoms of oral disease, $25.6\%$ of respondents answered that I felt sensitivity. Intraoral discomfortable symptoms in the respect of each age, under forty age had dental decay, over forty age had sensitivity of teeth. The more has a intake snack, the more has an oral disease and oral decayed tooth. As a whole of the above results in order to control oral health of the seafarers reasonably, time and economic limiting factors must be solved in the first. In planning oral health education, practicability should be emphasized especially.