• International Journal of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.55-62
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• 2024

International exchange implementing the Internet began inevitably due to the pandemic, but it provided Digital Nomads with new experiences in their lives using the Internet. This study the possibility and challenge of international exchange implementing the Internet identified. To this end, we explored its strengths and weaknesses through interviews and descriptions of students who participated in international exchange. As a result, we identified that students were positive in the diverse aspects of communication tools and ways, whereas they were negative because they felt difficulties in the physical environment, inaccessible physical conditions especially. They were also negative in the emotional exchange, an ice-breaking which needed much more time than offline exchange. Therefore, we identified in the case of designing or conducting student activities implementing the Internet, including international exchange, the possibility of activities implementing the Internet could be much more extended if their developer various programs considered in the introduction step.

• Advances in nano research
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• v.16 no.2
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• pp.201-215
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• 2024

The present research study emphasizes the utilization of mathematical simulation on a nanoelectromechanical systems (NEMS) sensor to facilitate the detection of injuries in players and equipment. Specifically, an investigation is conducted on the thermal buckling behavior of a small-scale truncated conical, cylindrical beam, which is fabricated using porous functionally graded (FG) material. The beam exhibits non-uniform characteristics in terms of porosity, thickness, and material distribution along both radial and axial directions. To assess the thermal buckling performance under various environmental heat conditions, classical and first-order nonlocal beam theories are employed. The governing equations for thermal stability are derived through the application of the energy technique and subsequently numerically solved using the extended differential quadratic technique (GDQM). The obtained results are comprehensively analyzed, taking into account the diverse range of effective parameters employed in this meticulous study.

• Advances in nano research
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• v.16 no.6
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• pp.579-591
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• 2024

This study explained the effects of radiation, magnetic field, and nanoparticle shape on the peristaltic flow of an Upper-Convected Maxwell nanofluid through a porous medium in an asymmetric channel for a better understanding of cooling and heating mechanisms in the presence of magnetic fields. These phenomena are modeled mathematically as a system of non-linear differential equations, that are solved under long-wavelength approximation and low Reynolds number conditions using the perturbation method. The results for nanofluid and temperature described the behavior of the pumping characteristics during their interaction with (the vertical position, thermal radiation, the shape of the nanoparticle, and the magnetic field) analytically and explained graphically. Also, the combined effects of thermal radiation parameters and some physical parameters on pressure rise, pressure gradient, velocity, and heat distribution are pointed out. Qualitatively, a reverse velocity appears with combined high radiation and Grashof number or combined high radiation and low volume flow rate. At high radiation, the spherical nanoparticle shape has the greatest effect on heat distribution.

• Structural Engineering and Mechanics
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• v.89 no.3
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• pp.323-334
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• 2024

Physical and chemical factors can cause traditional timber constructions to lose structural integrity. Knowing the dynamic properties of the building components is vital to avoid damage to the buildings from dynamic effects, a subset of physical effects. In this work, spruce and scotch pine wooden beams that had been strengthened in three distinct ways with carbon fiber strengthened polymer (CFRP) were investigated for changes in their dynamic properties. For this, CFRP was used to strengthening unstrengthened wooden beams in the form of bottom confinement, U-shaped confinement, and full confinement after the dynamic parameters of the beams were determined. By using experimental modal analysis with both free-free and fixed-fixed boundary conditions, the beams'initial natural frequencies were identified.

• Nonlinear Functional Analysis and Applications
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• v.29 no.3
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• pp.673-710
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• 2024

In this paper, we propose a modified Halpern's iterative scheme developed from a sequence of a new class of enriched nonspreading mappings and an enriched nonexpansive mapping in the setup of a real Hilbert space. Moreover, we prove strong convergence theorem of the proposed method under mild conditions on the control parameters. Also, we obtain some basic properties of our new class of enriched nonspreading mappings.

• Journal of Hydrogen and New Energy
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• v.35 no.4
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• pp.437-450
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• 2024

Sustainable shipping depends on eco-friendly energy solutions. This paper reviews methods for predicting marine fuel cell performance, including empirical approaches, physical modeling, data-driven techniques, and hybrid methods. Accurate prediction models tailored to the marine environment's unique conditions are crucial for operational efficiency. By evaluating the strengths and weaknesses of each method, this study provides a comprehensive analysis of effective strategies for forecasting polymer electrolyte membrane fuel cell and solid oxide fuel cell performance in marine applications. These insights contribute to the advancement of eco-friendly shipping technologies and enhance fuel cell performance in challenging marine environments.

• Advances in materials Research
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• v.13 no.4
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• pp.253-267
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• 2024

The current study attempts to discuss the effects of viscosity and locality on a fiber-reinforced thermoelastic solid. The problem is solved analytically in the context of the three-phase-lag model as well as the Green-Naghdi theory without energy dissipation (G-N II). The method of normal mode analysis is used to obtain analytical expressions for the displacement, stress, and temperature distributions. Compute the physical fields with suitable boundary conditions and perform numerical calculations using MATLAB programming. Comparisons are carried out with the results in the absence and presence of locality as well as viscosity. The locality and viscosity have great effects on all considered physical fields since the amplitudes of these quantities are vary. This procedure remains valid when a nonlocal elastic solid is replaced with an elastic one.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5295-5302
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• 2016

Objectives: A physically active lifestyle is important for cancer survivors. Therefore, this study was conducted to 1) provide population-based estimates of the prevalence of physical activity and sitting time, and 2) their correlates in Korean cancer survivors. Materials and Methods: This study analyzed a cancer survivor subsample (N=1,482) from 2008-2013 Korea National Health and Nutrition Examination Survey (KNHANES), data selected with a complex sampling design. Overall and subgroup-specific prevalences of physical activity and sitting time were estimated. Correlates of moderate- to vigorous-intensity physical activity ( MVPA) and sitting time were tested using age-group-specific hierarchical multiple regression models. Results: Overall adherence rate to physical activity guidelines was 34.9% (95% CI=31.5-38.4). Age-group-specific adherence rates were 41.1% (95% CI=36.3-45.9) in adults (30-64 years old), and 25.3% (95% CI=21.0-25.3) in older adults (65 years or older). Adults spent 213.33 minutes (95% CI=172.4-254.3) per week on MVPA and 55.3 minutes (95% CI=36.4-64.6) on sitting time per day. In adults, sitting time was significantly associated with employed status (B=28.0, p=0.046), smoking (B=-47.4, p=0.020), and number of comorbidity conditions (B=-13, p=.037). MVPA was significantly associated with marital status (B=134.9, p<0.001), employment status (B=98.12, p=.046), and years since cancer diagnosis (B=104.7, p=0.015). Older adults spent 162.2 minutes (95% CI=119.5-204.8) per week on MVPA and 63.0 minutes (95% CI=45.0-89.5) on sitting time per day. Their significant correlates were sex (B= -45.2, p=0.014), smoking (B=-70.14, p<0.001), and years since cancer diagnosis (B=37.0, p=0.024). Age (B=5.8, p=0.042) and marital status (B=83.8, p=0.033) were also significantly associated with MVPA in older adults. Conclusion: A majority of Korean cancer survivors do not sufficiently participate in physical activity. In general, older, unhealthier, non-working, and being unmarried were risk factors for physical inactivity. While this study informs public health policy makers and practitioners about physical activity intervention demand for cancer survivors, future investigations should address psychosocial mediators to better inform intervention programs.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.84-99
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• 2001

This study was carried out to acquire basic data necessary for the use of rice-straw chemical pulp. It investigated the proper bleaching conditions when rice-straw chemical pulp(alkaline sulfite-${Na_2}{S_2}{O_4}$) was bleached using the various kinds of bleaching agents by the two-stages bleaching methods. And, physical properties of pulps bleached with eight kinds of two-stages bleaching methods were tested. The results of this study were as follow; 1. The first-stage bleaching was conducted under the proper conditions with chlorine(C). And then, the proper conditions related to the calcium chlorite(H), hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of CH stage were determined to be 0.3% concentration of calcium chlorite, $30^{\circ}C$ of reaction temperature and 20min. of reaction time. For CP stage, the proper conditions of concentration of hydrogen peroxide, reaction temperature and reaction time were 1.5%, $60^{\circ}C$ and 90min., respectively. And for CY stage, the proper conditions were 0.5% concentration of sodium hydrosulfite, $40^{\circ}C$ of reaction temperature and 90min. of reaction time. 2. The first-stage bleaching was conducted under the proper conditions with chlorine dioxide(D). And then, the proper conditions related to the calcium chlorite(H), hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of DH stage were determined to be 0.5% concentration of calcium chlorite, $25^{\circ}C$ of reaction temperature and 5min. of reaction time. For DP stage, the proper conditions of concentration of hydrogen peroxide, reaction temperature and reaction time were 1.0%, $70^{\circ}C$ and 90min., respectively. And for DY stage, the proper conditions were 0.3% concentration of sodium hydrosulfite, $50^{\circ}C$ of reaction temperature and 20min. of reaction time. 3. The first-stage bleaching was conducted under the proper conditions with calcium chlorite(H). kAnd then, the proper conditions related to the hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of HP stage were determined to be 0.3% concentration of hydrogen peroxide, $30^{\circ}C$ of reaction temperature and 60min. of reaction time. For HY stage, the proper conditions of concentration of sodium hydrosulfite, reaction temperature and reaction time were 2.5%, $60^{\circ}C$ and 30min., respectively. 4. When the rice-straw chemical pulps were bleached with eight kinds of two-stages bleaching methods in the proper conditions mentioned above, respectively, the final brightnesses after CH, CP, CY, DH, DP, DY, HP, and HY bleachings were 62.0, 74.3, 61.4, 58.9, 66.9, 62.9, 50.4 and 60.1, respectively. And strengthes of pulps bleached with DP and DH methods were comparatively higher than those of pulps bleached with other bleaching methods.

• Journal of Society of Preventive Korean Medicine
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• v.17 no.2
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• pp.29-46
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• 2013

A survey conducted on 1,103 patients or caretakers visited Korean medical clinics and hospitals between August 25, 2011 to September 30, 2011 by the Ministry of Health and Welfares and Korea Institute for Health and Social Affairs was analyzed and obtained following results: 1. For sociodemographic distribution, female(813) outnumbered male(290) patients with majority of patients ranging from 30s to 60s. Married patients(793) outnumbered unwed(150) patients and 65.0% with higher than high school education. Statistical significance was seen in gender, age, marital status, and education level but no significant difference for status of employment, income level, and types of insurance between the clinics and hospitals. (P<0.05). 45.1% had less than \2,000,000 in monthly salary and most of coverage was provided by either regional or work insurance. 2. 67.9% of the patients rated health conditions to be better than average and 32.1% listed as poor. People in good health showed tendency to visit Korean medical facilities. Musculo-skeletal conditions such as arthritis, ankle sprain, lumbago, muscular injury, and frozen shoulder were common conditions, followed by gastric disorders, common cold and herbal tonics. No significant difference was observed between the clinics and hospitals for above conditions, but significance was seen in atopic dermatitis, stroke, and sequela from traffic accidents (P<0.05). 3. Ten most common conditions addressed at Korean medical facilities were lumbago, arthritis, muscular injury, back sprain, gastric disorders, ankle sprain, common cold, herbal tonics, frozen shoulder and stroke. Major treatment modalities rendered were herbal medicine, herbal supplements, acupuncture and moxibustion, cupping, tuina, and Korean midical physical therapy. No significant difference existed between the clinics and hospitals. 4. All modalities showed at least 85% effectiveness. No statistical significant difference between the clinics and hospitals except for herbal decoction. (P=0.0452) 5. 88.3% of responses showed treatment satisfaction with significant difference between the clinics and hospitals (P=0.002). The occurrence of side effects was at 2%, mostly corning from treating digestive, skin, kidney disorders and neurological issues. No significant difference was observed between the clinics and hospitals. From the above results, the typical population visiting Korean medical facilities can be summarized as being middle aged female with relatively higher education and moderately low income. The health condition is generally good and the purpose of visit is to receive traditional treatments of acupuncture, herbal medicine, and physical therapy. Treatment efficacy and satisfaction were high with no significant differences between the clinics and hospitals.