• Journal of the Society of Naval Architects of Korea
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• v.61 no.4
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• pp.267-277
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• 2024

The Sortie Generation Rate (SGR) is a critical performance indicator for carrier-based aircraft and is a key factor for the carrier design process. This study aims to analyze the factors that affect SGR and establish a representative Sortie Generation Process (SGP) along with simulation results to calculate SGR for a naval ship equipped to carry aircraft. Detailed SGR factors are identified from the perspectives of the aircraft, aviation personnel, and aircraft carrier during the flight preparation stage, and the SGP is established accordingly. As a representative, Korean Navy's CVX basic design is chosen for detailed analysis. The physical dimension and spots for the deck design with time and probabilistic data of SGP are considered to develop a queueing network model for SGR calculation. To consider the specific probabilistic features, the model was solved with discrete event simulation tools(SimPy and AnyLogic) where the results show great agreement. Such findings on SGR factors and calculation are expected to be incorporated in the future development of SGR calculation algorithms and also present guidelines for proper design of aircraft carrier based on concrete operation concept.

• Journal of Music and Human Behavior
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• v.21 no.2
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• pp.1-30
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• 2024

The purpose of this study is to develop a rhythm-based music intervention protocol to enhance timing regulation in children with ADHD and investigate its feasibility. For this purpose, a three-phase study was conducted involving ADHD children and typically developing children. In the first phase, group-specific baseline measurements were taken for auditory attention (KAT), motor timing, and perceptual timing. In the second phase, a rhythm-based music intervention protocol incorporating key factors was developed. In the third phase, the developed protocol was applied to ADHD children to investigate the variables affecting timing regulation and to verify its effectiveness. Results from the first phase revealed significant differences in the timing values of children with ADHD, particularly in tasks requiring discrimination of sound duration and precision in rhythm patterns. Additionally, exploratory factor analysis of KAT results and motor/perceptual timing identified three clusters: attentional responsiveness, attentional synchronization, and attentional sophistication. In the second phase, a protocol consisting of tasks involving synchronization, attentional shifting, and rhythm production at various difficulty levels was developed and validated for expert validity. In the third phase, individual application of the protocol to children with predominantly inattentive and hyperactive-impulsive ADHD subtypes demonstrated changes in timing regulation tasks. This study provided basic data for using rhythm as an effective facilitation tool that leads from voluntary to involuntary attention in children with ADHD.

• International Journal of Stem Cells
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• v.15 no.3
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• pp.324-333
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• 2022

Background and Objectives: This study was to investigate the role of microRNA-29a-3p (miR-29a-3p) in human bone marrow mesenchymal stem cells (hBMSCs), and its relationship with steroid-associated osteonecrosis. Methods and Results: The online tool GEO2R was used to screen out the differentially expressed genes (DEGs) in GSE123568 dataset. Quantitative real time-polymerase chain reaction (qRT-PCR) was performed to detect the expression of miR-29a-3p, forkhead box O3 (FOXO3), alkaline phosphatase (ALP), bone gamma-carboxyglutamate protein (OCN) and RUNX family transcription factor 2 (Runx2) in the hBMSCs isolated from the patients with steroid-associated osteonecrosis. CCK-8 assay was executed to measure cell viability; western blot assay was utilized to detect FOXO3, ALP, Runx2, OCN and β-catenin expression. Cell apoptosis and cell cycle were detected by flow cytometry. Immunofluorescence assay was used to detect the sub-cellular localization of β-catenin. Bioinformatics analysis and luciferase reporter gene assay were performed to confirm whether miR-29a-3p can combine with FOXO3 3'UTR. MiR-29a-3p was markedly up-regulated in the hBMSCs of patients with steroid-associated osteonecrosis, while FOXO3 mRNA was significantly down-regulated. Transfection of miR-29a-3p mimics significantly inhibited the hBMSCs' proliferation, osteogenic differentiation markers' expressions, including ALP, Runx2, OCN, and repressed the ALP activity, as well as promoted cell apoptosis and cell-cycle arrest. FOXO3 was identified as a target gene of miR-29a-3p, and miR-29a-3p can inhibit the expression of FOXO3 and β-catenin, and inhibition of miR-29a-3p promoted translocation of β-catenin to the nucleus. Conclusions: MiR-29a-3p can modulate FOXO3 expression and Wnt/β-catenin signaling to inhibit viability and osteogenic differentiation of hBMSCs, thereby promoting the development of steroid-associated osteonecrosis.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.295-301
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• 2023

This study was conducted to determine the optimal dipping time and concentration of gibberellin for improving the growth and quality of domestic cultivar 'Seolhyang' strawberry when using runner plants. Strawberry runner plants were collected on November 10th and soaked in GA₃ concentrations of 50, 100, and 150 mg·L^-1 for 30 and 60 minutes, respectively. After 75 days of planting, the growth results showed that in the 30-minute, 50 mg·L^-1 treatment, the crown diameter was thicker and the T/R ratio was lower, indicating better plant vitality. Runner length increased with lower gibberellin concentrations, particularly promoting vegetative growth. Photosynthetic efficiency was more influenced by gibberellin concentration than dipping time, and using concentrations above a certain threshold acted as a stress factor for runner plants, leading to decreased photosynthetic efficiency. For enhancing seedling growth, soaking with 50 mg·L^-1 of gibberellin for 30 minutes was found to be optimal. This study verified the effects of gibberellin treatment on strawberry runner plants to improve plant growth and quality, providing useful basic data for using gibberellin.

• Journal of Internet of Things and Convergence
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• v.10 no.3
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• pp.19-24
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• 2024

Recent advances in large-scale data processing technologies such as big data, cloud computing, and artificial intelligence have increased the demand for high-performance storage devices in data centers and enterprise environments. In particular, the fast data response speed of storage devices is a key factor that determines the overall system performance. Solid state drives (SSDs) based on the Non-Volatile Memory Express (NVMe) interface are gaining traction, but new bottlenecks are emerging in the process of handling large data input and output requests from multiple hosts simultaneously. SSDs typically process host requests by sequentially stacking them in an internal queue. When long transfer length requests are processed first, shorter requests wait longer, increasing the average response time. To solve this problem, data transfer timeout and data partitioning methods have been proposed, but they do not provide a fundamental solution. In this paper, we propose a dual queue based scheduling scheme (DQBS), which manages the data transfer order based on the request order in one queue and the transfer length in the other queue. Then, the request time and transmission length are comprehensively considered to determine the efficient data transmission order. This enables the balanced processing of long and short requests, thus reducing the overall average response time. The simulation results show that the proposed method outperforms the existing sequential processing method. This study presents a scheduling technique that maximizes data transfer efficiency in a high-performance SSD environment, which is expected to contribute to the development of next-generation high-performance storage systems

• Tunnel and Underground Space
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• v.34 no.4
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• pp.312-329
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• 2024

In various underground research projects such as energy storage and development and radioactive waste disposal targeting deep underground, the characteristics of permeable rock fractures that serve as major pathway of groundwater flow in deep rock aquifer are considered as an important evaluation factor in the design, construction, and operation of research facilities. In Korea, there is little research and database on the location and hydraulic characteristics of permeable rock fractures and the pattern of groundwater flow patterns that may occur between fractures in deep rock boreholes. In this paper, the hydraulic characteristics of permeable rock fractures in deep rock aquifer were evaluated through the analysis of geothermal gradient and pumping test data. First, the deep geothermal distribution was identified through temperature logging, and the geothermal gradient was obtained through linear regression analysis using temperature data by depth. In addition, the hydraulic characteristics of the fractured rock were analyzed using outflow temperature obtained from pumping tests. Ultimately, the potential location and hydraulic characteristics of permeable rock fractures, as well as groundwater flow within the boreholes, were evaluated by integrating and analyzing the geophysical logging and hydraulic testing data. The process and results of the evaluation of deep permeable rock fractures proposed in this study are expected to serve as foundational data for the successful implementation of underground research projects targeting deep rock aquifers.

• Journal of Food Hygiene and Safety
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• v.39 no.4
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• pp.299-303
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• 2024

Collagen, as an indicator of skin health, has been developed and used for various purposes. The development of an optimized collagen product suitable for use has become an important research field as the consumption of collagen increases. In particular, various efforts are being made to increase its absorption rate. In this study, the transdermal and oral epithelial cell permeabilities of various molecular weight collagen products sold in Korea were compared using a Franz diffusion cell system. The collagen absorption rate of oral mucosal tissue compared to skin epidermis/dermis tissue was significantly higher than that of collagen at M.W. 500 and 1,000 (approximately 10 times and 2 times higher, respectively). Additionally, collagen with a molecular weight of 500 Da increased the absorption rates by 2-3 times compared with products with a molecular weight of 1,000. Collagen with a molecular weight of 500 Da showed the highest Cmax and AUCt values, and all parameters in the oral mucosal cell test group were higher than those in the skin epidermis/dermis cells. Our findings suggest an increased absorption rate through oral mucosal cells rather than skin absorption, confirming that low molecular weight collagen is a major factor increasing the absorption rate.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.5
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• pp.533-549
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• 2024

Soil conditioning is a critical process when tunneling with an earth pressure balance (EPB) shield tunnel boring machine (TBM) to enhance performance. To determine the optimal additive injection conditions, it is important to understand the rheological properties of conditioned soil, which is typically assessed using a rheometer. However, a rheometer cannot simulate the actual process of muck discharge in a TBM. Therefore, in this study, a scaled-down model of an 8-meter-class EPB shield TBM chamber and screw conveyor, reduced by a factor of 1:20, was fabricated and its applicability was evaluated through laboratory experiments. A lab-scale model experiment was conducted on artificial sandy soil using foam and polymer as additives. The experimental results confirmed that screw torque was consistent with trends observed in previous laboratory pressurized vane shear test data, establishing a positive proportional relationship between screw torque and yield stress. The muck discharge efficiency according to foam injection ratio (FIR) showed similar values overall, but decreased slightly at 60% of FIR and when the polymer was added. In addition, the pressure distribution generated along the chamber and screw conveyor was assessed in a manner similar to the actual EPB TBM. This study demonstrates that the lab-scale screw conveyor model can be used to evaluate the shear properties and muck discharge efficiency.

• Asia-Pacific Journal of Business
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• v.15 no.3
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• pp.205-231
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• 2024

Purpose - The purpose of this study is to investigate the relationship between workplace bullying and defensive silence/acquiescent silence, and to examine a mediation model of job burnout. Design/methodolgy/approach - The survey questionnaires were distributed to 974 employees of a public R&D institute, financial industry, and public officials in Daejeon and Chungnam, and a total of 322 surveys were collected. 288 valid responses were used for the final data analysis using SPSS 21.0 and Amos 22.0. Descriptive statistics were used to identify demographic characteristics of the sample. Reliability analysis of the measurement was conducted using Cronbach's alpha coefficient, and confirmatory factor analysis (CFA) was performed to check the validity of the measurement. Hierarchical regressions were used to examine the relationship between the variables including the moderating effect of job calling. The mediating effect of job burnout and the moderated mediation effect of job calling was analyzed using bootstrapping with PROCESS Macro installed on SPSS 21.0. Findings - The findings of the study are as follows: First, workplace bullying had a significant positive effect on both defensive silence and acquiescent silence. Second, workplace bullying had a significant positive effect on job burnout. Third, job burnout had a significant positive effect on both defensive silence and acquiescent silence. Fourth, job burnout significantly mediated the relationship between workplace bullying and defensive silence, and between workplace bullying and acquiescent silence. Research implications or Originality - The results of this study show that workplace bullying is an important variable that must be managed, because workplace bullying leads to job burnout that can hinder the performance improvement and innovation activities of the organization, which in turn leads to organizational silence. On the other hand, in the research model, the job calling was used as a moderating variable to alleviate the positive effect of workplace bullying and job burnout on the defensive and acquiescent silence, but there was no significant moderating effect. In addition to the job calling, which is the moderating variable used in this study, it is judged that it is necessary to consider specific measures to prevent members from reaching job burnout and reduce silent behavior by investing appropriate job resources such as supporting colleagues, supervisors and leadership in the workplace.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.4
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• pp.77-85
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• 2014

A goal of Bizcool entrepreneurship education targeting on the youth falls on letting understand the process of starts-up, enhance entrepreneurship will and their business creativities rather than training trivial starts-up skills such as writing business plan for successful starts-up. The effects of education enable Bizcoo students to recognize rightly the concept of starts-up training and lead to spread out demand for entrepreneurship education. The feedback check-up for how entrepreneurship education affects students getting through of it is necessary and possible to bring its' improvement alternatives. Despite of such highlight, not many measuring tools and indexes of evaluating an effectiveness of entrepreneurship education are developed and studied up until. This research suggests for the optimal indexes for them. In specific, this research 49 the first question sets of evaluating an effectiveness of entrepreneurship education classified 3 large categories and 11 following sub categories each of them such as entrepreneurship orientation, creativity, entrepreneurship preparing activities etc,. representing embedding education effects though entrepreneurship education. This research carry out the empirical survey research utilizing driven question sets against 5 different Bizcools sampling 287 students. The survey research delivers the final 3 large categories and 8 following sub categories(Innovativeness, risk-taking, problem-solving potent, cooperative decision-making potent, efficient behavior capacity, data collecting potent, career search, starts-up search and preparation), and 38 measuring indexes by search and confirming factor analysis. This research never drop the confidence test over each indexes and obtain the proper figures. Last but not least, this research confirm the gap between starts-up club members and non members as to an effectiveness of entrepreneurship education and 9 different indexes.