• Progress in Superconductivity and Cryogenics
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• v.25 no.4
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• pp.19-23
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• 2023

The Second-generation high-temperature superconducting (HTS) Rare-Earth Barium Copper Oxide (REBCO) wire is a composite laminate having a multi-layer structure (8 or more layers). HTS wires will undergo multiple loads including the bending-tension loads during winding, high current density, and high magnetic fields. In particular, the wires are subjected to bending stress and magnetic field stress because HTS wires are wound around a circular bobbin when making a high-field magnetic. Each of the different laminated wires inevitably exhibits damage and fracture behavior of wire due to stress deformation, mismatches in thermal, physical, electrical, and magnetic properties. Therefore, when manufacturing high-field magnets and other applications, it is necessary to calculate the stress-strain experienced by high-temperature superconducting wire to present stable operating conditions in the product's use environment. In this study, the finite element model (FEM) was used to simulate the strain-stress characteristics of the HTS wire under high current density and magnetic field, and bending loads. In addition, the result of obtaining the neutral axis of the wire and the simulation result was compared with the theoretical calculation value and reviewed. As a result of the simulation using COMSOL Multiphysics, when a current of 100 A was applied to the wire, the current value showed the difference of 10^-9. The stress received by the wire was 501.9 MPa, which showed a theoretically calculated value of 500 MPa and difference of 0.38% between simulation and theoretical method. In addition, the displacement resulted is 30.0012 ㎛, which is very similar to the theoretically calculated value of 30 ㎛. Later, the amount of bending stress by the circular mandrel was received for each layer and the difference with the theoretically obtained the neutral axis result was compared and reviewed. This result will be used as basic data for manufacturing high-field magnets because it can be expanded and analyzed even in the case of wire with magnetic flux pinning.

• The Journal of Advanced Prosthodontics
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• v.15 no.5
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• pp.227-237
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• 2023

PURPOSE. This study aimed to assess and compare the color stability, flexural strength (FS), and surface roughness of occlusal splints fabricated from heat-cured acrylic resin, milled polymethyl methacrylate (PMMA)-based resin, and 3D-printed (PMMA) based-resin. MATERIALS AND METHODS. Samples of each type of resin were obtained, and baseline measurements of color and surface roughness were recorded. The specimens were divided into three groups (n = 10) and subjected to distinct aging protocols: thermomechanical cycling (TMC), simulated brushing (SB), and control (without aging). Final assessments of color and surface roughness and three-point bending test (ODM100; Odeme) were conducted, and data were statistically analyzed (2-way ANOVA, Tukey, P <.05). RESULTS. Across all resin types, the most significant increase in surface roughness (Ra) was observed after TMC (P < .05), with the 3D-printed resin exhibiting the lowest Ra (P < .05). After brushing, milled resin displayed the highest Ra (P < .05) and greater color alteration (∆E₀₀) compared to 3D-printed resin. The most substantial ∆E₀₀ was recorded after brushing for all resins, except for heat-cured resin subjected to TMC. Regardless of aging, milled resin exhibited the highest FS (P < .05), except when compared to 3D-printed resin subjected to TMC. Heat-cured resin exposed to TMC demonstrated the lowest FS, different (P < .05) from the control. Under control conditions, milled resin exhibited the highest FS, different (P < .05) from the brushed group. 3D-printed resin subjected to TMC displayed the highest FS (P < .05). CONCLUSION. Among the tested resins, 3D-printed resin demonstrated superior longevity, characterized by minimal surface roughness and color alterations. Aging had a negligible impact on its mechanical properties.

• Korean Journal of Community Nutrition
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• v.28 no.6
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• pp.480-494
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• 2023

Objectives: This study sought to assess the effectiveness of community-based nutrition counseling on improving nutritional status, managing complex chronic diseases, and enhancing the quality of life for elderly individuals with chronic conditions, particularly in older adults with high levels of food insecurity and multiple chronic illnesses. Methods: Thirty elderly subjects with diabetes and hypertension who were registered at local Senior Welfare Center received individualized nutrition counseling, based on their Nutrition Quotient for the Elderly (NQ-E) index. Over a 16-week period, they received tailored counseling and underwent various health and nutritional assessments. The final analysis included 28 participants after two dropped out. Data analysis was conducted using the SPSS v28.0. Results: The subjects were over 70, with multiple chronic diseases including diabetes and hypertension and predominantly female. After 16 weeks, significant improvements were observed in the subjects' grip strength, and HbA1c levels, as well as in their NQ-E scores, indicating improved dietary balance and diversity. There were no significant improvements in the 'Moderation' subdomain of the NQ-E index, suggesting that this aspect requires further attention in nutritional counseling. The subjects' nutritional risk scores (NSI) were also significantly decreased, indicating less nutritional risk. Lastly, as measured by the SF-36K, the subjects' quality of life showed significant improvement in several domains including physical role performance and social function. Conclusions: This study demonstrates that tailored nutrition counseling, based on the NQ-E index, can improve elderly health, manage chronic diseases, and enhance quality of life. This approach potentially broadens the scope of community nutritionists' roles within an aging society. However, additional research is necessary to evaluate these interventions' long-term effects and sustainability.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.843-856
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• 2023

The global surge in maritime traffic has resulted in an increased number of ship collisions, leading to significant economic, environmental, physical, and human damage. The causes of these maritime accidents are multifaceted, often arising from a combination of crew judgment errors, negligence, complexity of navigation routes, weather conditions, and technical deficiencies in the vessels. Given the intricate nuances and contextual information inherent in each incident, a methodology capable of deeply understanding the semantics and context of sentences is imperative. Accordingly, this study utilized the SentenceBERT model to analyze maritime safety tribunal decisions over the last 20 years in the Busan Sea area, which encapsulated data on ship collision incidents. The analysis revealed important keywords potentially responsible for these incidents. Cluster analysis based on the frequency of specific keyword appearances was conducted and visualized. This information can serve as foundational data for the preemptive identification of accident causes and the development of strategies for collision prevention and response.

• Korean Journal of Culture and Social Issue
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• v.16 no.1
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• pp.1-18
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• 2010

This study examines the characteristics of traffic accidents involving elderly pedestrians by analyzing relevant data vis-à-vis fatal pedestrian accidents and proposes solutions to reduce such accidents. We analyzed 3,853 cases of fatal accidents involving elderly pedestrians and 1,786 cases involving younger pedestrian (these cases reflect accidents that occurred from 2005 to 2008). The results show that accidents involving the elderly occur more frequently in rural areas than urban areas, especially in autumn; this condition applies even in situations where the elderly exhibit compensation behaviors such as walking on safer roads. We found that elderly pedestrians exhibit a defective behavior in crossing roads, especially in complicated road conditions where intersections and turning/reversing vehicles represent a menacing threat. These characteristics could be explained by the degenerated physical/mental ability of the elderly and by psychological factors such as reduced level of self-confidence.

• Information Systems Review
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• v.25 no.4
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• pp.113-130
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• 2023

Due to economic development and increasing gross national income, the number of automobiles continues to rise, leading to a serious issue of illegal parking due to limited road conditions and insufficient parking facilities. Illegal parking causes significant inconvenience and displeasure to people and can even result in accidents and loss of lives. The severity of accidents and their consequences, related to the growing number of vehicles and illegal parking, is escalating, particularly in the metropolitan areas. Consequently, efforts are being made to address this problem as a cause of social issues and come up with measures to reduce illegal parking. In particular, half of the public complaints in the metropolitan area are related to illegal parking, and the highest physical and human damage occurs in Gyeonggi. Thus, this study aims to use machine learning techniques based on data related to illegal parking in Suwon city, Gyeonggi, to categorize regional characteristics and propose effective measures to crack down on illegal parking. Additionally, practical, social, policy, and legal measures to decrease illegal parking in the metropolitan area are suggested. This study has academic significance in that it solved the problem of illegal parking, which is mentioned as one of the social problems that cause traffic congestion, by classifying regional characteristics using K-prototype, a machine learning algorithm. Furthermore, the results of this study contribute to practical and social aspects by providing measures to decrease illegal parking in the metropolitan area.

• Journal of Industrial Convergence
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• v.21 no.11
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• pp.135-145
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• 2023

The purpose of this study is to investigate the effect of a forest experience program on the lung capacity, health & fitness, emotional intelligence, and psychological well-being of local children.This study was conducted on 3rd and 4th grade elementary school students for 12 weeks from July 10 to September 30, 2022, at a local children's center in D City. Changes were analyzed and verified using t-test. Verified. The changes in the lung capacity, health & fitness, emotional intelligence, and psychological well-being of the experimental group and the control group were analyzed and verified using t-test.For the changes in lung capacity and health & fitness, there was a statistically significant difference between the control group and the experimental group in lung capacity (t=24.56, p<.05), and there was also a statistically significant difference between the two groups in cardiorespiratory endurance among the elements of health & fitness (t=16.64, p<.05). As for the changes in emotional intelligence and psychological well-being, there was statistically significant differences between the experimental group and the control group in the emotional intelligence (t=2.31, p<.05) and in psychological well-being (t=3.21, p<.05). Through this study, the positive effects of the forest experience program were confirmed, and it is believed that institutional arrangements are needed to improve children's participation conditions by expanding forest experience education spaces and developing customized forest experience programs to suit the characteristics of the region.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.4
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• pp.325-332
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• 2008

To characterize the initiation, propagation and termination of Cochlodinium polykrikoides blooms in the southeast coastal waters of Korea, 2007, we have analyzed the data set of phytoplankton composition, physical and chemical water properties, and meterological data. The development of C. polykrikoides bloom in 2007 can be summarized in three steps. The first stage from middle of July to end of August was characterized by an unusually persistent and strong southerly wind. C. polykrikoides blooms established already by the strong wind in the middle of south coastal waters were advected intermittently into the study area. Accordingly, highly variable cell densities of C. polykrikoides were observed. At the second stage a favorable growing conditions for C. polykrikoides was developed, which was directed by changes in wind direction from south to northeast and thus enhanced transportation of offshore waters into inshore (August 8 to 30). C. polykrikoides bloom occurred through typical mechanism and showed high cell density. The last stage was represented by disappearance of C. polykrikoides. Typoon 'Nari' carrying heavy rain brought an unfavorable habitat to C. polykrikoides. Low saline condition formed in coastal water due to typoon effects continuously drove the dominant species to diatoms and flagellates which were prevailing over C. polykrikoides in this circumstances(from the middle of September). These stepwise processes could be the causative mechanism of the extraordinarily persistent C. polykrikoides bloom observed in southeast coastal water of Korea, 2007.

• Food Science of Animal Resources
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• v.44 no.1
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• pp.51-73
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• 2024

This study investigated how birth weight differences in piglets affected carcass and muscle fiber properties as well as meat quality at slaughter. Within litters, piglets were grouped according to their birth weight as either normal (NBW; 1.62-1.73 kg) or low (LBW; 1.18-1.29 kg). At 5 weeks of age, NBW piglets were randomly transitioned to control (C) or isocaloric high fat diets derived from non-dairy (HF), while LBW piglets were randomly transitioned to high fat diets derived from non-dairy (HF) or dairy sources (HFHD). Piglets were reared in individual pens under standardized housing and feeding conditions. Live weight was recorded weekly, and pigs were slaughtered at 12 weeks of age. Hot carcass weights, dressing percentages, lean meat yield, and primal cut proportions were determined. The m. longissimus thoracis was collected from the right side of the carcass for measurement of physical and chemical properties of meat and muscle fiber characteristics. Results indicated that LBW pigs compensated for their live weight compared to NBW pigs at 6 weeks of age. The mean muscle fiber diameter of LBW-HFHD group is significantly higher than NBW-C and NBW-HF group, and the type I muscle fiber diameter is significantly higher than NBW-C group. Dairy fat inclusion in LBW pig diet reduced carcass back fat thickness. This increased the calculated lean meat yield to be comparable to that of NBW pigs fed a commercial diet. Incorporating dairy-sourced high-fat into LBW pigs' diets appears to be an effective strategy for producing carcasses equivalent to NBW pigs.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.1
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• pp.85-93
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• 2024

The monitoring of environmental information (e.g. noise, dust, vibration, temperature, humidity) is crucial to the safe and sustainable operation of a construction site. However, commercial sensors exhibit certain drawbacks when applied on-site. First, the installation cost is prohibitively high. Second, these sensors have been engineered without considering the rugged and harsh conditions of a construction site, resulting in error-prone sensing. Third, construction sites are compelled to allocate additional resources in terms of manpower, expenses, and physical spaces to accommodate individual sensors. This research developed an integrated sensing module to measure the environmental information in construction site. The sensing module slashes the installation cost to 3.3%, is robust enough to harsh and outdoor sites, and consolidates multiple sensors into a single unit. The sensing module also supports GPS, LTE, and real-time sensing. The evaluation showed remarkable results including 97.5% accuracy and 99.9% precision in noise measurement, an 89.7% accuracy in dust measurement, and a 93.5% reliability in data transmission. This research empowers the collection of substantial volumes and high-quality environmental data from construction sites, providing invaluable support to decision-making process. These encompass objective regulatory compliance checking, simulations of environmental data dispersion, and the development of environmental mitigation strategies.