• Journal of the Korean Society of Physical Medicine
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• v.16 no.2
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• pp.53-62
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• 2021

PURPOSE: Social participation is essential for stroke survivors. Although participation restrictions are affected by several factors, a few studies have focused on the effects of living in a particular residential area (urban versus rural) on the participation restrictions after a stroke. This study examined the factors affecting participation restrictions in stroke survivors according to the residential area. METHODS: One hundred sixty-six stroke patients (including 130 living in urban areas and 36 living in rural areas) were recruited for this study. The Korean Modified Barthel Index (K-MBI) was used to assess the activities of daily living (ADL). The Korean Mini-Mental Examination Status (MMSE-K) was used to assess cognition. The motor function was evaluated using the Fugl-Meyer function assessment (FMA). Path analysis was used to test the hypothesized model of participation restriction. RESULTS: The proposed path model showed good fit indices. In rural and urban areas, the direct effects were significant between the ADL and participation restrictions (β = -.673 and -.457, respectively). For urban areas, the direct effects were significant between cognition and participation restrictions (β = -.252). In both area types, motor function and cognition had a significant direct effect on the ADL. CONCLUSION: For urban community-dwelling stroke survivors, the ADL and cognition had direct effects on participation restrictions. For rural area stroke survivors, the ADL had direct effects on participation restrictions. Activity level exercise programs help reduce the participation restrictions. Moreover, it is essential to address cognition training to improve participation in urban community-dwelling stroke survivors.

• Journal of Industrial Convergence
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• v.20 no.2
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• pp.21-27
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• 2022

Purpose: The purpose of this study is to investigate the structural relationship between self-directed learning, online class environment, and learning satisfaction of general high school students. 219 12th grade students in Sejong B High School responded to the survey questionnaire. For data analysis, correlation analysis and structural equation models were implemented. Results are as follows. First, there was a moderate or higher correlation between self-directed learning, online class environment, and learning satisfaction. Second, the model fit of the structural model among variables was good. Self-directed learning had an effect on the online class environment, and the online class environment had a positive effect on learning satisfaction. However, self-directed learning had no statistically significant effect on learning satisfaction. The researcher found the implication that learners' online class satisfaction showed a synergistic effect when students' self-directed learning ability and educators' excellent class environment are created. Also, the researcher proposed to analyze online learning satisfaction by comprehensively considering the individual, family, and school factors of various learners.

• Journal of Korean Academy of Nursing
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• v.52 no.4
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• pp.421-434
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• 2022

Purpose: This study aimed to examine the effect of parental self-esteem on late school-aged children's media device addiction by mediating marital conflict and children's self-esteem. Methods: This study used data from the 11th (2018) Panel Study on Korean Children. The participants consisted of 1,082 family triads (fathers, mothers, and children). Data were collected using the Rosenberg Self-Esteem Scale, Marital Conflict Scale, and K-Internet Addiction Scale. The data were analyzed using structural equation modeling with SPSS/WIN 27.0 and Mplus 8.7. Results: The final model showed a good fit for the data. Children's media device addiction was directly related to mothers' self-esteem, mothers' marital conflict, and children's self-esteem. Fathers' self-esteem had a significant indirect effect on children's media device addiction by mediating both fathers' and mothers' marital conflict. In addition, mothers' self-esteem had a significant indirect effect on children's media device addiction by mediating mothers' marital conflict. Conclusion: The findings indicates that self-esteem and marital conflict for both fathers and mothers have a significant effect on children's media device addiction. It suggests that more attention might be given to fathers and mothers in developing interventions to prevent children's media device addiction.

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.108-115
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• 2023

Numerous psychotropic and addictive substances possess structural features similar to those of β-phenethylamine (β-PEA). In this study, we selected 29 β-PEA derivatives and determined their structure-activity relationship (SAR) to their ability to inhibit dopamine (DA) reuptake; conducted docking simulation for two selected compounds; and identified their potential functionals. The compounds were subdivided into arylethylamines, 2-(alkyl amino)-1-arylalkan-1-one derivatives and alkyl 2-phenyl-2-(piperidin-2-yl)acetate derivatives. An aromatic group, alkyl group, and alkylamine derivative were attached to the arylethylamine and 2-(alkyl amino)-1-arylalkan-1-one derivatives. The inhibitory effect of the compounds on dopamine reuptake increased in the order of the compounds substituted with phenyl, thiophenyl, and substituted phenyl groups in the aromatic position; compounds with longer alkyl groups and smaller ring-sized compounds at the alkylamine position showed stronger inhibitory activities. Docking simulation conducted for two compounds, 9 and 28, showed that the (S)-form of compound 9 was more stable than the (R)-form, with a good fit into the binding site covered by helices 1, 3, and 6 of human dopamine transporter (hDAT). In contrast, the (R, S)-configuration of compound 28 was more stable than that of other isomers and was firmly placed in the binding pocket of DAT bound to DA. DA-induced endocytosis of dopamine D₂ receptors was inhibited when they were co-expressed with DAT, which lowered extracellular DA levels, and uninhibited when they were pretreated with compound 9 or 28. In summary, this study revealed critical structural features responsible for the inhibition of DA reuptake and the functional role of DA reuptake inhibitors in regulating D₂ receptor function.

• Journal of Korean Philosophical Society
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• no.94
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• pp.53-87
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• 2011

Leibniz regards a corporeal substance, which is composed of monads, as 'one substance' and tries to prove that it has a true unity. This position seems to be contradictionary to his Monadology. Therefore, many scholars have ignored Leibniz's stand that corporeal substance is 'one substance', or consider this only as a stand from his theory of substance in his early works, which has been discarded afterwards. This Research will show that Leibniz adheres to this position throughout his lifetime; that although Leibniz uses the concepts such as substantial form and substantial bond to explain his stand, but the concept of substancial bond doesn't fit in with his philosophical system; that to explain the unity of the corporeal substance, the concept of substancial form and the theory of preestablished harmony are sufficient; and that nevertheless the stand that the corporeal substance is 'one substance' inconsistent with the position that the monad is 'one substance'; and that if Leibniz abandons that stand, the theory of the corporeal substance is a good foundation of his panorganism.

• Journal of Trauma and Injury
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• v.36 no.1
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• pp.15-21
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• 2023

Purpose: Dental avulsion injuries have a poor prognosis that largely depends on the immediate steps taken to manage the avulsed tooth. A lack of knowledge about the initial management can lead to tooth loss, with further adverse implications for esthetics, phonetics, and overall growth and function. Hence, the present study aimed to assess parents' knowledge regarding dental avulsion and the variables associated with their knowledge of avulsion injuries. Methods: A series of closed-ended questions on parents' knowledge regarding avulsion, such as immediate management, storage media, handling, and urgency of visiting the dentist, was asked. Univariate associations between the outcomes were assessed using the Pearson chi-square test. The chisquare goodness-of-fit test was used to check whether the sample data were representative of the population. Results: In total, 211 mothers and 149 fathers were included, of whom 46.7% had experienced dental trauma during their own childhood. Sixty-one percent of mothers believed that they knew everything necessary about tooth avulsion and its management. A significant number of participants who thought that they had a good level of knowledge about avulsion chose water, tissue, or paper wrap to transport the tooth, and preferred tap water, alcohol, or antiseptic to clean the avulsed tooth. Conclusions: Both mothers and fathers had poor knowledge about tooth avulsion, indicating that there is an immediate need for educational programs focusing on this issue. Since a substantial proportion of participants believed incorrect information, it is vital to disseminate accurate information.

• Journal of Home Health Care Nursing
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• v.30 no.1
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• pp.48-58
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• 2023

Purpose: The purpose of this study was to construct a nomogram for predicting difficulty in peripheral intravenous cannulation (DPIVC) for adult inpatients. Methods: This study conducted a secondary analysis of data from the intravenous cannulation cohort by intravenous specialist nurses at a tertiary hospital in Seoul. Overall, 504 patients were included; of these, 166 (32.9%) patients with failed cannulation in the first intravenous cannulation attempt were included in the case group, while the remaining 338 patients were included in the control group. The nomogram was built with the identified risk factors using a multiple logistic regression analysis. The model performance was analyzed using the Hosmer-Lemeshow test, area under the curve (AUC), and calibration plot. Results: Five factors, including vein diameter, vein visibility, chronic kidney disease, diabetes, and chemotherapy, were risk factors of DPIVC. The nomogram showed good discrimination with an AUC of 0.81 (95% confidence interval: 0.80-0.82) by the sample data and 0.79 (95% confidence interval: 0.74-0.84) by bootstrapping validation. The Hosmer-Lemeshow goodness-of-fit test showed a p-value of 0.694, and the calibration curve of the nomogram showed high coherence between the predicted and actual probabilities of DPIVC. Conclusion: This nomogram can be used in clinical practice by nurses to predict DPIVC probability. Future studies are required, including those on factors possibly affecting intravenous cannulation.

• Geomechanics and Engineering
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• v.32 no.1
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• pp.49-68
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• 2023

The three-dimensional failure criterion is essential for maintaining wellbore stability and sand production problem. The convenient factor for a stable wellbore is mud weight and borehole orientation, i.e., mud window design and selection of borehole trajectory. This study proposes a new three-dimensional failure criterion with linear relation of three in-situ principal stresses. The number of failure criteria executed to understand the phenomenon of rock failure under in-situ stresses is the Mohr-Coulomb criterion, Hoek-Brown criterion, Mogi-Coulomb criterion, and many more. A new failure criterion is the extended Mohr-Coulomb failure criterion with the influence of intermediate principal stress (σ₂). The influence of intermediate principal stress is considered as a weighting of (σ₂) on the mean effective stress. The triaxial compression test data for eleven rock types are taken from the literature for calibration of material constant and validation of failure prediction. The predictions on rock samples using new criteria are the best fit with the triaxial compression test data points. Here, Drucker-Prager and the Mogi-Coulomb criterion are also implemented to predict the failure for eleven different rock types. It has been observed that the Drucker-Prager criterion gave over prediction of rock failure. On the contrary, the Mogi-Coulomb criterion gave an equally good prediction of rock failure as our proposed new 3D failure criterion. Based on the yield surface of a new 3D linear criterion it gave the safest prediction for the failure of the rock. A new linear failure criterion is recommended for the unique solution as a linear relation of the principal stresses rather than the dual solution by the Mogi-Coulomb criterion.

• Advances in concrete construction
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• v.15 no.3
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• pp.161-170
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• 2023

Ultra-high-performance concrete (UHPC) is produced using high amount of cementitious materials, very low water/cementitious materials ratio, fine-sized fillers, and steel fibers. Due to the dense microstructure of UHPC, it possesses very high strength, elasticity, and durability. Besides that, the UHPC exhibits high ductility and fracture toughness due to presence of fibers in its matrix. While the high ductility of UHPC allows it to undergo high strain/deflection before failure, the high fracture toughness of UHPC greatly enhances its capacity to absorb impact energy without allowing the formation of severe cracking or penetration by the impactor. These advantages with UHPC make it a suitable material for construction of the structural members subjected to special loading conditions. In this research work, the UHPC mixtures having three different dosages of steel fibers (2%, 4% and 6% by weight corresponding to 0.67%, 1.33% and 2% by volume) were characterized in terms of their mechanical properties including facture toughness, before using these concrete mixtures for casting the slab specimens, which were tested under high-energy impact loading with the help of a drop-weight impact test setup. The effect of fiber content on the impact energy absorption capacity and central deflection of the slab specimens were investigated and the equations correlating fiber content with the energy absorption capacity and central deflection were obtained with high degrees of fit. Finite element modeling (FEM) was performed to simulate the behavior of the slabs under impact loading. The FEM results were found to be in good agreement with their corresponding experimentally generated results.

• Wind and Structures
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• v.34 no.2
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• pp.231-257
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• 2022

Transmission lines systems are important components of the electrical power infrastructure. However, these systems are vulnerable to damage from high wind events such as hurricanes. This study presents the results from a 1:50 scale aeroelastic model of a multi-span transmission lines system subjected to simulated hurricane winds. The transmission lines system considered in this study consists of three lattice towers, four spans of conductors and two end-frames. The aeroelastic tests were conducted at the NSF NHERI Wall of Wind Experimental Facility (WOW EF) at the Florida International University (FIU). A horizontal distortion scaling technique was used in order to fit the entire model on the WOW turntable. The system was tested at various wind speeds ranging from 35 m/s to 78 m/s (equivalent full-scale speeds) for varying wind directions. A system identification (SID) technique was used to evaluate experimental-based along-wind aerodynamic damping coefficients and compare with their theoretical counterparts. Comparisons were done for two aeroelastic models: (i) a self-supported lattice tower, and (ii) a multi-span transmission lines system. A buffeting analysis was conducted to estimate the response of the conductors and compare it to measured experimental values. The responses of the single lattice tower and the multi-span transmission lines system were compared. The coupling effects seem to drastically change the aerodynamic damping of the system, compared to the single lattice tower case. The estimation of the drag forces on the conductors are in good agreement with their experimental counterparts. The incorporation of the change in turbulence intensity along the height of the towers appears to better estimate the response of the transmission tower, in comparison with previous methods which assumed constant turbulence intensity. Dynamic amplification factors and gust effect factors were computed, and comparisons were made with code specific values. The resonance contribution is shown to reach a maximum of 18% and 30% of the peak response of the stand-alone tower and entire system, respectively.