• Journal of The Korean Society of Integrative Medicine
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• v.9 no.4
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• pp.291-298
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• 2021

Purpose: The Pedisole is a newly developed shoe-mounted wearable assessment system for analyzing balance and gait. This study aimed to determine the reliability and validity of the parameters provided by the system for static balance and gait analysis of healthy adults. Methods: This study included 38 healthy adults (22.4±1.9 years) with no history of injury in the lower limbs. All participants were asked to perform balance and gait tasks for undertaking measurements. For analysis of balance, both the smart Pedisole and Pedoscan systems were concurrently used to analyze the path length of the center of pressure (COP) and the weight ratio of the left and right for 10 s. Gait was measured using the smart Pedisole and GaitRite walkway systems simultaneously. The participants walked at a self-selected preferred gait speed. The cadence, stance time, swing time, and step time were used to analyze gait characteristics. Using the paired t-test, the intra-class coefficient correlation (ICC) was calculated for reliability. The Spearman correlation was used to assess the validity of the measurements. In total, data for balance from 36 participants and the gait profiles of 37 participants were evaluated. Results: There were significant differences between the COP path lengths (p<.050) derived from the two systems, and a significant correlation was found for COP path length (r=.382~.523) for static balance. The ICC for COP path length and weight ratio was found to be greater than .687, indicating moderate agreement in balance parameters. The ICC of gait parameters was found to be greater than .697 except for stance time, and there was significant correlation (r=.678~.922) with the GaitRite system. Conclusion: The newly developed smart insole-type Pedisole system and the related application are useful, reliable, and valid tools for balance and gait analysis compared to the gold standard Pedoscan and the GaitRite systems in healthy individuals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.386-391
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• 2021

Turbocharging is becoming a key technology for both diesel and gasoline engines. Regarding gasoline engines, turbocharging can help reduce carbon dioxide (CO2) emissions when used in conjunction with other technologies. This paper presents measurements of the turbine efficiency of pulsating flow in a twin-scroll turbocharger for gasoline engines. A cold gas test bench with a pulse generator was manufactured. The turbine efficiencies were calculated using the measured data of the instantaneous pressure and temperature of the inlet and exit of the turbine. The measurements were carried out at turbine speeds from 60,000 to 100,000 rpm under a pulsating flow of 25.0 Hz and 33.0 Hz. The turbine efficiencies ranged from 0.517 to 0.544. At the pulse frequency, 33.3 Hz, the variations in efficiency were 7.7% and 2.6% at turbine speeds of 60,000 rpm and 100,000 rpm, respectively. The turbine efficiency of the pulsating flow compared to those of steady flow was 7.0% and 3.0% lower at a turbine speed of 60,000 rpm and 100,000 rpm, respectively. The pulsating flow deteriorated the turbine efficiency, but the effects of pulsating flow decreased with increasing turbine speed.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.447-452
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• 2020

Extratropical cyclone in winter season is very important in safe operation of ships because it is a major cause of marine accidents due to its strong power. In this study, we used meteorological data, to analyze extratropical cyclones occurring near the 1st Pacific polar front from December 2019 to February 2020. The analysis results are as follows. During those three months, we recorded 41 extratropical cyclones, 8 of which were remarkably developed. The central pressure of the strongest cyclone was 947hPa. The highest number of cyclones were generated in the East P acific Ocean around J apan (16), followed by the areas around Korea, the East China Sea, and the southern Sea of J apan. The cyclones followed five major tracks with a common northeast pattern. We thus concluded that the optimal route for a ship encountering an extratropical cyclone in the North P acific in winter would be south of the cyclone's center traveling eastbound and north of the center traveling westbound.

• Journal of the Economic Geographical Society of Korea
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• v.23 no.4
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• pp.373-394
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• 2020

The strengthening of multilateral international sanctions against North Korea has raised questions as to how effective they are in exerting pressure on the country's economy. In this paper, we address this question by examining their impact on the country's integration into regional and global apparel production networks. North Korea has in the past decade become an increasingly competitive exporter of apparel on the basis of consignment-based processing arrangements. Official trade data shows a sharp drop in North Korean exports of clothing since the sectoral ban in 2017. There is evidence to suggest, however, that exports have continued on a more informal and clandestine basis. North Korea's integration into apparel production networks has also taken the form of the dispatch of workers to factories in China's northeastern border regions. Yet there is evidence that the recent sanctions imposed on such practices has similarly led to illicit practices such as working on visitors' visas, often with the help of Chinese enterprises and local government. The resilience of North Korea's integration into apparel production networks follows a capitalist logic and is result of the highly profitable nature of apparel production for all actors concerned and a correspondingly strong desire to evade sanctions. As such, the analysis contributes to the literature on sanctions that suggests that the measures may contribute to emergence of growing informal and illicit practices and to the role of the clandestine economy.

• Journal of the Korean GEO-environmental Society
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• v.12 no.4
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• pp.33-41
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• 2011

In case of building up port facilities on soft ground, unsymmetrical surcharge of embankment, which make the excess pore water pressure to increase, causes to occur lateral displacement due to plasticity of soil. A study on lateral displacement and settlement of the caisson, which is installed on improved ground, was accomplished. The field measurement data and calculated values obtained from FEM program of Plaxis were compared and analyzed. For numerical analysis, the properties of soils, constructions stage and time were considered. Lateral displacement was measured at the point of inclinometers installed in front of caisson. Settlement was measured at the center of extra embankment behind of caisson. Comparison of measured and calculated for lateral displacement showed that the calculated value was greater than the measured, and increasing trend was different. The calculated value showed step increasing as step extra embankment applied, whereas the measured gradually was increased. For settlement of embankment, the amount of both measured and calculated were similar, but the trend was different like that of lateral movement.

• Journal of The Korean Society of Clinical Toxicology
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• v.18 no.2
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• pp.110-115
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• 2020

Purpose: Acute kidney injury (AKI) in patients with glyphosate poisoning has a poor prognosis. This study aimed to predict the risk factors for AKI in patients with glyphosate poisoning at the emergency department (ED). Methods: Clinical data on glyphosate poisoning patients at ED who were older than 18 years were collected retrospectively between January 2013 and December 2019. The clinical characteristics and clinical outcomes of the AKI group in patients with glyphosate poisoning were compared with the non-AKI (NAKI) group. Results: Of 63 glyphosate poisoning patients, AKI was observed in 15 (23.8%). The AKI patients group showed the following: old age (p=0.038), low systolic blood pressure (p=0.021), large amount of ingestion (p=0.026), delayed hospital visits (p=0.009), high white blood cells (WBC) (p<0.001), high neutrophil counts (p<0.001), high neutrophil-lymphocyte (LN) ratios (p<0.001), high serum potassium (p=0.005), low arterial blood pH (p=0.015), and low pO2 (p=0.021), low bicarbonate (p=0.009), and high Poisoning Severity Score (PSS) (p<0.001). AKI patients required hemodialysis, ventilator care (p<0.001, p=0.002), and inotropics (p<0.001). They also showed more intensive care unit admission (p<0.001), longer hospitalization (p<0.001), and high mortality (p<0.001). Logistic multivariate regression analysis showed that high WBCs (OR, 1.223) and increased LN ratios (OR, 1.414) were independently associated with the occurrence of AKI. Conclusion: In patients with glyphosate poisoning at ED, high WBCs and increased LN ratios can help predict the occurrence of AKI.

• Journal of Korean Society of Disaster and Security
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• v.14 no.1
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• pp.9-21
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• 2021

Recently, the importance of eco-friendly power generation facility using renewable energy has newly appeared. Hydropower plant is a very important source of electricity generation and supply which is very important to secure safety because it is commonly connected with multi facility and operated on a large scale. In this study, a scenario-based analysis method was suggested to assess vulnerability of a penstock system caused by water hammer commonly occurred in the operation of hydropower plants. A hypothetical hydropower plant was used to demonstrate the applicability of a transient analysis model. In order to verify reliability of the model, the prediction of pressure behaviors were compared with the results of commercial model (SIMSEN) and measured data, then a real hydroelectric power plant was applied to develop all potential water hammer scenarios during the actual operation. The scenario-based simulation and vulnerability assessment for water hammer in the penstock system were performed with internal and external load conditions. The simulation results indicated that the vulnerability of a penstock system was varied with the operating conditions of hydropower facilities and significantly affected by load combination consisting of different load scenarios. The proposed numerical method could be an useful tool for the vulnerabilityty assessment of the hydropower plants due to water hammer.

• The Journal of Engineering Geology
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• v.31 no.2
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• pp.199-209
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• 2021

This paper is written to evaluate the ground stability according to the construction of Jeju 2nd airport. Sumgol is the unique characteristics of Jeju soil, which is used to evaluate the ground stability of the airport. The research contents are as follows. 1) The geotechnical characteristics for Jeju 2nd airport was analyzed, and the Sumgol and geotechnical properties were calculated based on the existing geotechnical survey data. 2) The divided sections of Jeju 2nd airport were modeled to evaluate the ground stability after determining the section (runway and airport facilities) which have the different soil and loading properties. 3) The stability and deformation ranges of the airport ground were identified through numerical analysis. The entire airport was divided into three sections to analyze the stability of Jeju 2nd airport, and calculated the stresses, settlements, and strains of each section by computer numerical analysis modeling. For modeling, the ground and load conditions were examined, also pavement conditions for each airport ground section were examined. From the analysis results of each section according to the ground conditions, the vertical settlements were analyzed as 0.11~0.18 m and the sum of effective stress and pore water pressure were 92.75~445 kPa. These results were made by taking into account the Sumgol of the bottom ground without reinforcement, also the soil strength parameters of the airport ground were reduced for computer modeling, Therefore, if proper reinforcements are applied to the ground of Jeju 2nd airport, sufficient airport ground stability can be secured.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.747-758
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• 2022

This study aimed to identify the factors that influence depression in stressed adults by age. Data were extracted from the 7th Korea National Health and Nutrition Examination Survey, covering 3,333 adults aged 20 to 59 years who were highly aware of stress. Linear regression analysis was performed using the IBM SPSS 25.0 program. The study found that in the case of people in their 20s, education level, health-related quality of life, obesity, weight change, smoking, and subjective body type were significant influencing factors, with an explanatory power of 60.3%. In the case of people in their 30s, gender, household income level, living with spouse, economic activity, health-related quality of life, food intake, obesity, alcohol consumption, smoking, and subjective health were significant influencing factors, with an explanatory power of 30.3%. For people in their 40s, household income level, living with spouse, economic activity, health-related quality of life, smoking, aerobic exercise, and subjective health were significant influencing factors, with an explanatory power of 34.4%. For people in their 50s, gender, education level, income, economic activity, health-related quality of life, protein intake, fat intake, high blood pressure, diabetes, weight control, aerobic exercise, subjective health, and subjective body type were significant influencing factors, with an explanatory power of 42.3%. Therefore, as it was found through this study that the factors affecting depression in stressed adults differ by age, it is necessary to establish an intervention strategy for each age when trying to lower depression in stressed adults.

• Journal of the Korean Applied Science and Technology
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• v.39 no.1
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• pp.96-107
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• 2022

The purpose of this study was to demonstrate the effects of 8weeks Kettlebell training on the FMS and Balance in Middle school baseball player. Fourteen middle school baseball players were randomly assigned to a kettlebell group (n=8) and a control group (n=6), and kettlebell training was applied twice a week for 60 minutes. And the FMS, Y-balance test and static and dynamic balance test using smart shoes were tested before and after kettlebell training. Repeated two-way ANOVA measures was performed both before and after the exercise to verify the effect of kettlebell training. Also, if there was an interaction between time and group, a paired sample t-test was performed for each group. As a results of the study, FMS score showed a significant difference in IL (Inline Lunge) and TS(Total Score), and there was no significant difference in other variables of FMS. The YBT score showed a significant difference in all YBT variables except for the left AT. And the balance test using smart shoes, there was no significant interaction effect between group and period in all variables. In conclusion, it was found that the application of kettlebell training in middle school baseball players had an effects on the FMS and YBT scores related to functional movement and functional balance, but it did not affect the static/dynamic balance test using smart shoes evaluated by the foot pressure method. It seems that the results of this study can be provided as basic data necessary for planning a training program for middle school baseball players.