• Journal of Technology Innovation
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• v.12 no.3
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• pp.1-24
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• 2004

E-Learning is another way of teaching and learning. E-learning is a networked phenomenon allowing for instant revisions and distribution, and goes beyond training and instruction to the delivery of information and tools to improve performance. The benefits of e-learning are many, including cost-effectiveness, enhanced responsiveness to change, consistency, timely content, flexible accessibility, and providing customer value. The proponents of e-learning stress the importance of using communities of interest to support and enhance the learning process. They also emphasizes that people learn more effectively when they interact and are involved with other people participating in similar endeavors. Although the role of e-learning in higher education has significantly increased, the resistance to new technology by professors and lecturers in university and colleges worldwide remains high. The purpose of this study is to identify the determinants of attitude and planned behavior toward e-learning class in universities. A survey methodology was used to investigate a proposed model of influence, and structural equation modeling was used to analyze the results. The hypothesized model was largely supported by this analysis, and the overall results indicate that attitude toward e-learning systems is mostly influenced by the perceived ease of use as well as the level of perceived usefulness, where both factors are influenced by years of experiences in using cyber system and the technical support level. As in other TAM related research, it can be concluded that the perceived ease of use and perceived usefulness contribute to the future use of e-learning system.

• Restorative Dentistry and Endodontics
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• v.37 no.2
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• pp.74-78
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• 2012

Objectives: This study aimed to evaluate the relationship between the cyclic fatigue of a K3 file and internal stress intentionally induced until the activation of the autostop function of the torque-controlled motor. Materials and Methods: K3 (Sybron Endo) .04 and .06 taper, size 25, 30, 35, 40 and 45 were used in this study. To give the internal stress, the K3 files were put into the .02 taper Endo-Training-Bloc (Dentsply Maillefer) until the activation of the auto-stop function of the torque-controlled motor. The rotation speed was 300 rpm and torque value was 1.0 $N{\cdot}cm$. K3 were grouped by the number of induced internal stress and randomly distributed to 4 experimental groups (n = 10, Stress 0 [control], Stress 1, Stress 2 and Stress 3). For measuring the cyclic fatigue failure, the K3 files were worked against a sloped glass block and time for file separation was recorded. Data was statistically analyzed Statistical analyses were performed using two-way ANOVA and Duncan post-hoc test at p < 0.05 level. Results: Except .04 taper size 30 in Stress 1 group, there were statistically significant differences in time for file separation between control and all experimental groups. K3 with .04 taper showed higher cyclic fatigue resistance than those of .06 taper. Conclusion: In the limitation of this study, the cyclic fatigue of the K3 file was influenced by the accumulated internal stress from use until the auto-stop function was activated by the torque-controlled motor. Therefore, clinicians should avoid the reuse of the K3 file that has undergone auto-stops.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.6
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• pp.585-592
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• 2021

Cisplatin has been reported to cause side effects such as muscle wasting in humans and rodents. The physiological mechanisms involved in preventing muscle wasting, such as the regulation of AKT, PGC1-α, and autophagy-related factor FOXO3a by MuRF 1 and Atrogin-1, remain unclear following different types of exercise and in various skeletal muscle types. Eight-week-old male Wistar rats (n = 34) were assigned to one of four groups: control (CON, n = 6), cisplatin injection (1 mg/kg) without exercise (CC, n = 8), cisplatin (1 mg/kg) + resistance exercise (CRE, n = 9) group, and cisplatin (1 mg/kg) + aerobic exercise (CAE, n = 11). The CRE group performed progressive ladder exercise (starting with 10% of body weight on a 1-m ladder with 2-cm-interval grids, at 85°) for 8 weeks. The CAE group exercised by treadmill running (20 m/min for 60 min daily, 4 times/week) for 8 weeks. Compared with the CC group, the levels of the autophagy-related factors BNIP3, Beclin 1, LC3-II/I ratio, p62, and FOXO3a in the gastrocnemius and soleus muscles were significantly decreased in the CRE and CAE groups. The CRE and CAE groups further showed significantly decreased MuRF 1 and Atrogin-1 levels and increased phosphorylation of AKT, FOXO3a, and PGC1-α. These results suggest that both ladder and aerobic exercise directly affected muscle wasting by modulating the AKT/PGC1-α/FOXO3a signaling pathways regardless of the skeletal muscle type.

• International Journal of Computer Science & Network Security
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• v.22 no.10
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• pp.291-297
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• 2022

Modern challenges in the educational environment force scientists and practitioners to search for an adequate answer. In particular, the war in Ukraine demonstrated the importance of developing information competence as one of the main means of distinguishing true information from a whole stream of fake news. This is especially relevant in connection with the introduction of distance learning when students must find and process a large amount of information on their own. Therefore, the purpose of the article is to analyze the training of higher education students through the prism of acquiring the necessary level of informational competence in war conditions. For this, general scientific and special research methods, as well as the experimental method, were used. In the results, the peculiarities of the interpretation of information competence in the distance form of education among modern researchers are determined, the psychological components of resistance to fakes are analyzed. Based on the conducted empirical measurements, it was established that thorough work on student education gives positive skills when working independently with Internet materials, strengthens the ability to distinguish false information and propaganda from the real state of affairs. The conclusions summarize the results of the empirical research and suggest ways to improve the situation with the formation of information competence.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.87-94
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• 2023

TMCP(Thermo Mechanical Control Process) steel was continuously cast (CC) by varying the argon gas flow rate and vacuum time in the Ruhrstahl Heraeus (RH) refining process. Using the CC specimens, the distribution of the inclusions and the mechanical properties were evaluated. A lot of oxides and Al-O type inclusions were observed. The average Vickers hardness did not show a constant, but showed dispersion in a certain range. The shape and scale parameters of the CC specimen with an argon gas flow rate of 160Nm³ and a vacuum time of 12 minutes was the best. Mechanical properties (tensile strength, yield strength and elongation) were consistent with the Weibull probability distribution analysis results. The impact resistance was the best for CC specimens with an argon flow rate of 140 Nm³ and a vacuum time of 12 minutes. Although the inclusions and mechanical properties of the CC specimens were evaluated according to the argon gas flow rate and vacuum time, these values were no significant difference.

• Journal of the Korea Society of Computer and Information
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• v.28 no.8
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• pp.1-10
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• 2023

Recently, NAND flash memories have replaced magnetic disks due to non-volatility, high capacity and high resistance, in various computer systems but it has disadvantages which are the limited lifespan and imbalanced operation latency. Therefore, many page replacement policies have been studied to overcome the disadvantages of NAND flash memories. Although it is clear that these policies reflect execution characteristics of various environments and applications, researches on the foundation-policy decision for disk buffer management are insufficient. Thus, in this paper, we propose a foundation-policy recommendation model, called FRM for effectively utilizing NAND flash memories. FRM proposes a suitable page replacement policy by classifying and analyzing characteristics of workloads through machine learning. As an implementation case, we introduce FRM with a disk buffer management policy and in experiment results, prediction accuracy and weighted average of FRM shows 92.85% and 88.97%, by training dataset and validation dataset for foundation disk buffer management policy, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.1
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• pp.44-54
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• 2023

In this study, the second-order Nomoto's nonlinear expansion model was implemented as a Tagaki-Sugeno fuzzy model based on the heading angular velocity to design the automatic steering system of a ship considering nonlinear elements. A Tagaki-Sugeno fuzzy PID controller was designed using the applied fuzzy membership functions from the Tagaki-Sugeno fuzzy model. The linear models and fuzzy membership functions of each operating point of a given nonlinear expansion model were simultaneously tuned using a genetic algorithm. It was confirmed that the implemented Tagaki-Sugeno fuzzy model could accurately describe the given nonlinear expansion model through the Zig-Zag experiment. The optimal parameters of the sub-PID controller for each operating point of the Tagaki-Sugeno fuzzy model were searched using a genetic algorithm. The evaluation function for searching the optimal parameters considered the route extension due to course deviation and the resistance component of the ship by steering. By adding a penalty function to the evaluation function, the performance of the automatic steering system of the ship could be evaluated to track the set course without overshooting when changing the course. It was confirmed that the sub-PID controller for each operating point followed the set course to minimize the evaluation function without overshoot when changing the course. The outputs of the tuned sub-PID controllers were combined in a weighted average method using the membership functions of the Tagaki-Sugeno fuzzy model. The proposed Tagaki-Sugeno fuzzy PID controller was applied to the second-order Nomoto's nonlinear expansion model. As a result of examining the transient response characteristics for the set course change, it was confirmed that the set course tracking was satisfactorily performed.

• Tuberculosis and Respiratory Diseases
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• v.86 no.3
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• pp.234-244
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• 2023

Background: Effective treatment of fluoroquinolone-resistant multidrug-resistant tuberculosis (FQr-MDR-TB) is difficult because of the limited number of available core anti-TB drugs and high rates of resistance to anti-TB drugs other than FQs. However, few studies have examined anti-TB drugs that are effective in treating patients with FQr-MDR-TB in a real-world setting. Methods: The impact of anti-TB drug use on treatment outcomes in patients with pulmonary FQr-MDR-TB was retrospectively evaluated using a nationwide integrated TB database (Korean Tuberculosis and Post-Tuberculosis). Data from 2011 to 2017 were included. Results: The study population consisted of 1,082 patients with FQr-MDR-TB. The overall treatment outcomes were as follows: treatment success (69.7%), death (13.7%), lost to follow-up or not evaluated (12.8%), and treatment failure (3.9%). On a propensity-score-matched multivariate logistic regression analysis, the use of bedaquiline (BDQ), linezolid (LZD), levofloxacin (LFX), cycloserine (CS), ethambutol (EMB), pyrazinamide, kanamycin (KM), prothionamide (PTO), and para-aminosalicylic acid against susceptible strains increased the treatment success rate (vs. unfavorable outcomes). The use of LFX, CS, EMB, and PTO against susceptible strains decreased the mortality (vs. treatment success). Conclusion: A therapeutic regimen guided by drug-susceptibility testing can improve the treatment of patients with pulmonary FQr-MDR-TB. In addition to core anti-TB drugs, such as BDQ and LZD, treatment of susceptible strains with later-generation FQs and KM may be beneficial for FQr-MDR-TB patients with limited treatment options.

• Computers and Concrete
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• v.32 no.2
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• pp.217-232
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• 2023

Numerous studies have been performed on the behavior of pile foundations in cold regions. This study first attempted to employ artificial neural networks (ANN) to predict pile-bearing capacity focusing on pile data recorded primarily on cold regions. As the ANN technique has disadvantages such as finding global minima or slower convergence rates, this study in the second phase deals with the development of an ANN-based predictive model improved with an Elephant herding optimizer (EHO), Dragonfly Algorithm (DA), Genetic Algorithm (GA), and Evolution Strategy (ES) methods for predicting the piles' bearing capacity. The network inputs included the pile geometrical features, pile area (m²), pile length (m), internal friction angle along the pile body and pile tip (Ø°), and effective vertical stress. The MLP model pile's output was the ultimate bearing capacity. A sensitivity analysis was performed to determine the optimum parameters to select the best predictive model. A trial-and-error technique was also used to find the optimum network architecture and the number of hidden nodes. According to the results, there is a good consistency between the pile-bearing DA-MLP-predicted capacities and the measured bearing capacities. Based on the R2 and determination coefficient as 0.90364 and 0.8643 for testing and training datasets, respectively, it is suggested that the DA-MLP model can be effectively implemented with higher reliability, efficiency, and practicability to predict the bearing capacity of piles.

• Advances in nano research
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• v.15 no.6
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• pp.567-577
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• 2023

The killing of bacteria by mechanical forces on nanopatterned surfaces has been defined as a mechano-bactericidal effect. Inspired by nature, this method is a new-generation technology that does not cause toxic effects and antibiotic resistance. This study aimed to simulate the mechano-bactericidal effect of nanopatterned surfaces' geometric parameters and material properties against three implant-derived bacterial species. Here, in silico models were developed to explain the interactions between the bacterial cell and the nanopatterned surface. Numerical solutions were performed based on the finite element method. Elastic and creep deformation models of bacterial cells were created. Maximum deformation, maximum stress, maximum strain, as well as mortality of the cells were calculated. The results showed that increasing the peak sharpness and decreasing the width of the nanopatterns increased the maximum deformation, stress, and strain in the walls of the three bacterial cells. The increase in spacing between nanopatterns increased the maximum deformation, stress, and strain in E. coli and P. aeruginosa cell walls it decreased in S. aureus. The decrease in width with the increase in sharpness and spacing increased the mortality of E. coli and P. aeruginosa cells, the same values did not cause mortality in S. aureus cells. In addition, it was determined that using different materials for nanopatterns did not cause a significant change in stress, strain, and deformation. This study will accelerate and promote the production of more efficient mechano-bactericidal implant surfaces by modeling the geometric structures and material properties of nanopatterned surfaces together.