• Geomechanics and Engineering
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• v.6 no.3
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• pp.249-262
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• 2014

Tire chips and tire chips-soil mixtures can be used as alternative fill material in many civil engineering applications. In this study, the potential benefits of using tire chips as lightweight material to improve the bearing capacity and the settlement behavior of sand slope was investigated experimentally. For this aim, a series of direct shear and model loading tests were conducted. In direct shear tests, the effect of contents of the tire chips on the shear strength parameters of sand was investigated. Different mixing ratios of 0, 5, 10, 15 and 20% by volume were used and the optimum mixing ratio was obtained. Then, laboratory model tests were performed on a model strip footing on sand slope reinforced with randomly distributed tire chips. The loading tests were carried out on sand slope with relative density of 65% and the slope angle of $30^{\circ}C$. In the loading tests the percentage of tire chips to sand was taken as same as in direct shear tests. The results indicated that at the same loading level the settlement of strip footing on sand-tire chips mixture was about 30% less than in the case of pure sand. Addition of tire chips to sand increases BCR (bearing capacity ratio) from 1.17 to 1.88 with respect to tire chips content. The maximum BCR is attained at tire chips content of 10%.

• Journal of the Korean Ceramic Society
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• v.53 no.5
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• pp.483-488
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• 2016

Anode supported solid oxide fuel cells (SOFCs), consisting of Ni+YSZ anode, YSZ electrolyte, and LSM+YSZ cathode, were fabricated and constant current tested with direct internal reforming of methane (steam to carbon ratio ~ 2) as well as hydrogen fuel at $800^{\circ}C$. The cell, operated under direct internal reforming conditions, showed relatively rapid degradation (~ 1.6 % voltage drop) for 95 h; the cells with hydrogen fuel operated stably for 170 h. Power density and impedance spectra were also measured before and after the tests, and post-test analyses were conducted on the anode parts using SEM / EDS. The results indicate that the performance degradation of the cell operated with internal reforming can be attributed to carbon depositions on the anode, which increase the resistance against anode gas transport and deactivate the Ni catalyst. Thus, the present study shows that direct internal reforming SOFCs cannot be stably operated even under the condition of S/C ratio of ~ 2, probably due to non-uniform mixture (methane and steam) gas flow.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1227-1234
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• 2017

The two-degree-of-freedom direct drive induction motor, which is capable of linear, rotary and helical motion, has a wide application in special industry such as industrial robot arms. It is inevitable that the linear motion and rotary motion generate coupling effect on each other on account of the high integration. The analysis of this effect has great significance in the research of two-degree-of-freedom motors, which is also crucial to realize precision control of them. The coupling factor considering the coupling effect is proposed and addressed by 3D finite element method. Then the corrected mathematical model is presented by importing the coupling factor. The results from it are verified by 3D finite element model and prototype test, which validates the corrected mathematical model.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.386-390
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• 2014

Purpose: We aimed to investigate whether visuomotor function would be modulated, when healthy subjects performed tracking task after tDCS application over the primary sensorimotor cortex (SM1) in the non-dominant hemisphere. Methods: Thirty four right-handed healthy participants were enrolled, who randomly and evenly divided into two groups, real tDCS group and sham control group. Direct current with intensity of 1 mA was delivered over SM1 for 15 minutes. After tDCS, tracking task was measured, and their performance was calculated by an accuracy index (AI). Results: No significant difference in AI at the baseline between the two groups was observed. The AI of the real tDCS group was significantly increased after electrical stimulation, compared to the sham control group. Two way ANOVA with repeated measurement showed a significant finding in a large main effects of time and group-by-repeated test interaction. Conclusion: This study indicated that application of the anodal tDCS over the SM1 could facilitate higher visuomotor coordination, compared to sham tDCS group. These findings suggest possibility that tDCS can be used as adjuvant brain modulator for improvement of motor accuracy in healthy individuals as well as patients with brain injury.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.6 s.171
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• pp.152-158
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• 2005

The stress conditions acting on the practical structure are complex, and thus most cracks existing in the practical structures are under mixed-mode loading conditions. The effect of shear load component of mixed-mode loading acts more greatly in the stage of crack initiation and initial propagation than crack propagation stage. Hence, research on the behavior in the stage of crack initiation and initial propagation need to be examined in order to evaluate behavior of mixed-mode fatigue cracks. In this study, the crack tip displacement(CTD) was measured by using the direct measuring method(DMM). We examined the behavior at crack tip by determining crack opening load$(P_{op})$. From the test results, the propagation behavior of mixed-mode fatigue cracks was evaluated by considering mixed-mode crack closure. Also, we examined the characteristic of crack propagation under mixed-mode loading with crack propagation direction.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.169-181
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• 2021

The study aims to investigate the direct effects of business management practices in terms of financial, marketing, human resources, and logistics operations practices on sales revenue and profitability growth of freight forwarding businesses. A quantitative research design and partial least square-structural equation modeling were used to examine the direct effects of the exogenous and endogenous variables. The study reveals that financial, marketing, and human resources practices have a positive and significant effect on sales revenue growth. Furthermore, marketing and logistics operations have a positive and significant effect on profitability growth in the context of freight forwarding in the Philippines, particularly in its country's capital. As the current study only examines the direct effects of business management practices, other researchers may also want to consider identifying other variables as mediation and moderation to test other indirect effects on the financial performance of the business. The findings of the study can significantly benefit the freight industry to consider addressing other challenges or make use of the paper to further develop their strategies and practices to improve their financial performance.

• The Korean Journal of Emergency Medical Services
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• v.23 no.1
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• pp.7-17
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• 2019

Purpose: The aim of this study was to verify the necessity of endotracheal intubation through video laryngoscope and to provide basic data to inform the provision of video laryngoscope education. Methods: Eighty paramedic students participated in this study. A survey was conducted from November 5, 2018 to December 7, 2018. Data were analyzed with independent t-tests, and the chi-squared test. Results: The video laryngoscope is a highly usable instrument that can easily be applied during training. The instrument provides better visual evaluation of the normal airway (p=.004), the airway in case of cervical collar and head fixation (p=.000), and the airway in case of tongue edema (p=.000). The time of endotracheal intubation in the normal airway was significantly less with the video laryngoscope compared with the direct laryngoscope. The success rate of tracheal intubation was significantly higher in the video laryngoscope group than in the direct laryngoscope. Conclusion: This study suggests the necessity of education on endotracheal intubation through video laryngoscope in the professional airway maintenance training course of emergency department students. The video laryngoscope is easier to apply than the direct laryngoscope in cases of intubation in various clinical situations.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.69-81
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• 2021

The aim of this paper is to identify the key determinants in the Gulf Cooperation Council (GCC) countries for Foreign Direct Investment (FDI) inflows by using a balanced data panel for the period from 1995 to 2018. This study covers GCC countries in their entirety. The study uses ten explanatory variables, namely, trade ratio, gross domestic product, external balance, fuel exports, gross savings, international tourism, military expenditure, net foreign assets, services value added, and total natural resources. The authors have tried to find the best fit model from the differences methods considered such as OLS, GLS regression with the help of Hausman test, and country by country regressions as additional analysis. The study revealed a significantly positive association between inflation, trade ratio, gross domestic product, gross savings, and net foreign assets with FDI. On the contrary, international tourism was revealed to have a negative association with FDI. The sample of all GCC countries chosen for this study has not been considered widely by any earlier study. Moreover, this study covered many determinants of FDI that add to the previous literature. It is a significant contribution to the current research body and stresses the originality of this paper.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.278-291
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• 2021

This paper applies load variation method to predict speed-power-rpm relationship along with propulsive performances in regular head waves, and to derive overload factors (ITTC, 2018). 'Calm-water tests' and 'resistance test in waves' are used. The modified overload factors are proposed taking non-linearity into consideration, and applied to the direct powering, and resistance and thrust identity method. These indirect methods are evaluated through comparing the speed-power-rpm relationships with those obtained from the resistance and self-propulsion tests in calm water and in waves. The objective ship is KVLCC2. The load variation method predicts well the speed-power-rpm relationship and propulsion performances in waves. The direct powering method with modified overload factors also predicts well. The resistance and thrust identity method with modified overload factor predicts with a little difference. The direct powering method with overload factors predicts with a relatively larger difference.

• Journal of Distribution Science
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• v.20 no.4
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• pp.77-83
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• 2022

Purpose: This study aims to find the impact of international trade cooperation and distribution on foreign direct investment (FDI). The study also tests the impact of lag variables of trade cooperation and distribution on FDI in the future. Research design, data, and methodology: Autoregressive Distributed Lag model is applied to analyze the impact of chosen variables such as total trade (TRADE), trade openness (OPEN), the exchange rate (EXR), inflation (INF), and gross domestic growth (GDP) on FDI. Quarterly data is collected from Vietnam General Statistic Office, Vietnam General Department of Customs, International Monetary Fund, and The World Bank from 2006 to 2020. Stata 14 software is used to analyze the regression and test variables. Results: The findings indicate that TRADE, OPEN, INF, GDP, and their lags affect both positively and negatively on FDI in different periods. While OPEN still expresses an unclear impact on FDI. Moreover, this study proves that the FDI of a nation is influenced by international cooperation. Conclusions: This study indicates the importance of international trade cooperation and distribution in not only attracting foreign investment sources but also developing the economy. Findings are necessary bases for governments or authorities in signing international trade agreements in the future.