• 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 Korean Applied Science and Technology
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• v.38 no.3
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• pp.762-770
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• 2021

The purpose of this study was to analyze the effect on the vertical ground reaction force, the elapsed time, and the center of pressure factors during gait by maepsi exercise program, which is a whole body exercise, to middle-aged women for 8 weeks. A total of 25 subjects participated in this study, 13 in the exercise group(age, 41±4.4 years; heigh, 162.5±5.8cm; weight, 57.8±6.7kg; body mass, 21.9±2.4kg/m2) and 12 in the control group(age, 41.1±5.6 years; height, 160.9±5.5 cm; weight, 576.2±8.1 kg; body mass, 21.7±2.9 kg/m2). In the exercise group, the maepsi exercise program consisting of 7 areas, 23 types and 77 movements, was conducted 3 times a week for 8 weeks. Two-way repeated measures ANOVA was performed to verify the ground reaction force factors during gait, and the post-test was analyzed with bonferroni adjustment(a=.05). In the exercise group, compared to the control group, the exercise group showed higher values than the control group in the elapsed time to FMWA and FPO, vertical ground reaction force at FMWA and FPO, and RMS factors of COP in the AP direction. Therefore, it was found that the 8-week maepsi exercise program improved the acceleration and deceleration exercise functions of middle-aged women who performed gait.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.1
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• pp.1-14
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• 2021

The Ministry of Environment of Korea has been releasing Asiatic black bears since 2004 at Jirisan National Park. It exceeded the target number of Asiatic black bears in 2018. As of July 2020, in addition to 67 traceable bears, many Asiatic black bears are dispersed outside Jirisan National Park. Jirisan National Park is a very dense place with more than 3 million visitors every year. In this study, the roads and trails through Jirisan National Park were considered to be the main dispersion factors of Asiatic black bears, and the fragmentation analysis was conducted. As of July 2017, the length of roads and trails in Jirisan National Park was 363.4km. Based on this, Jirisan National Park was fragmented into 163 patches. There is only one place that maintains a single area of more than 50㎢ that is suitable for large mammals to inhabit, and 141 places are less than 5㎢. There are 6 patches of 24 to 200㎢ area suitable for living of large mammals including Asiatic black bears, in Jirisan National Park. Compared to the announcement made by the Korea National Park Service in 2014, activities of Asiatic black bears were rare in areas below 5㎢ area and the frequency of activities was high in more than 20㎢ area. This shows that human activities in protected areas such as national parks can directly affect the activities of wild animals, including Asiatic black bears. Therefore, efforts should be made to improve the habitat of Asiatic black bears by reducing the pressure of visiting for Jirisan National Park. In addition, as a result of analyzing the fragmentation of the park's natural conservation zone 107.7km, 45% of the trail of Jirisan National Park, was opened, which is more fragmentation than other use zones. The park nature conservation zone accounts for about 32% of the total area of Jirisan National Park, but the average patch area is only 2.93㎢ and seven large shelters are located. Therefore the Asiatic black bears are negatively affected. This is the result of inconsistent national park use zone setting and actual park management. In overseas countries, research is active on the negative effects of human activity on ecosystems in protected areas. However, there is a lack of research of that in Korea. Thus, that research is required for protection area management in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.192-199
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• 2020

The blower erosion phenomenon was investigated to develop a long-life blower with a volume flow rate of 10,000 ㎥/min with the required total pressure efficiency of 83% or more. The blower performance and blower erosion were predicted through numerical analysis by computational fluid dynamics(CFD). The conditions used for numerical analysis were an air volume of 16,200 ㎥/min, a rotation speed of 893 rpm, and a temperature of 330℃. The specific gravity, particle size, and amount of the dust was 3.15, 90 ㎛~212 ㎛, and is 265 kg/min, respectively. To examine the effects of a dust deflector on erosion, erosion analysis was performed by comparing the models with and without a dust deflector. Numerical analysis showed that when the dust deflector is installed, the average tended to decrease by 167% in the impeller and 133% in the boss. CFD using the Finne's model for erosion revealed a parallel restitution coefficient of 1 and a perpendicular restitution coefficient of 0.1. The blower performance of case 5 was 691.7 mmAq, and the efficiency was 83.3% when the rotation speed and the air volume flow rate were 880 rpm and 16,200 ㎥/min, respectively.

• Korean Journal of Organic Agriculture
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• v.29 no.3
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• pp.415-427
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• 2021

It is generally recognized that high stocking density can increase the risk of immune dysfunction and reduction in productivity cause of elevated stress in broiler farm. The domestic livestock industry is implementing a certification system for animal welfare and livestock farms to reduce the problem of dense breeding. This study compared broiler from the general farm and animal welfare farm to confirm the effectiveness of animal welfare farms against stress. Gas concentrations in a farm of general and animal welfare farms were analyzed, blood (n=10) of the 28-day-old broiler was collected, the partial pressure of the gas in the blood was analyzed using whole blood, and biochemical factors and hormones were analyzed using the serum. Glycogen and L-lactate are analyzed using ELISA kit on finely pulverized muscles (n=10). CO₂ and NH₃ levels in the farm were significantly higher in general farm. Partial carbon dioxide tension (PCO₂) in blood was significantly higher and partial oxygen tension (PO₂) was significantly lower in the general farm. Creatinine (CREA), glucose (GLU), aspartateaminotransferase (AST), and creatinekinase (CK) in the blood were significantly higher in the general farm, and total protein (TP) and globulin (GLOB) were significantly higher in animal welfare farm. Blood corticosterone and norepinephrine were significantly higher in general farm and epinephrine was significantly higher in animal welfare farm. These results imply that animal welfare farm provides a stress-reduced breeding environment.

• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.22-28
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• 2021

Combustion characteristics were examined experimentally for a swirl-stabilized double cone premixed burner nozzle used for industrial gas turbines for power generation. An original model and a variant with a different fuel injection pattern are tested to compare their combustion characteristics such as NOx, CO and stability in pressurized conditions with single burner-flame and in an ambient multi-flame conditions with multi-burners. Test results show that NOx emissions are smaller for the variant, whose number of fuel holes is reduced with the same total area of fuel holes, in ambient and pressurized single-flame conditions with single burner, which results from enhanced fuel/air mixing due to a higher penetration of fuel into the air stream. The multi-burnerflame test results show that NOx emissions are smaller for the variant due to reduced flame interactions, which, on the contrary, slightly reduces the stability margin. On-site test results fromin an actual power plants also show that NOx emissions are reduced for the variant, compared with the original one, which is in agreement with the lab test results stated above.

• 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.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.23-29
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• 2022

Although tropical cyclones with wind speeds weaker than 17 ms^-1 (weak tropical cyclones: WTCs) can cause significant damage, particularly over the Seoul metropolitan area, only a few studies have focused on WTC activity over South Korea. In this study, we found that WTC activity is likely associated with the Pacific Decadal Oscillation (PDO). During the negative phases of the PDO, landfall frequency of WTCs increased significantly compared to the positive phases at 95% confidence level. When related to the negative phases of the PDO, a positive relative vorticity anomaly is found in the northern sector of the western North Pacific while a negative relative vorticity anomaly and enhanced vertical wind shear prevail in the southern sector of the WNP. These factors are favorable for the northward shift of the genesis location of tropical cyclones on average, thereby reducing the total lifetime of WTCs. Moreover, a high-pressure anomaly over the Japanese islands would shift a tropical cyclone track westward in addition to the landfall location. Consequently, the effects of the topographical friction and the Yellow Sea Bottom Cold Water on a tropical cyclone may increase. These conditions could result in a weaker lifetime maximum intensity and landfall intensity, ultimately resulting in WTCs becoming more frequent over South Korea during the negative phases of the PDO.

• Journal of the Korean Geotechnical Society
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• v.37 no.11
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• pp.71-81
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• 2021

The purpose of this study is liquefaction phenomenon was simulated using the 1g shaking table test. Analysis of liquefaction and Re-liquefaction behavior according to the ground conditions was analyzed when an embankment exists above the ground. The soil used in the experiment was silica sand and the ground composition was a liquefied layer of 50cm (Case 1), a non-liquefied layer of 17.5cm and a liquefied layer of 32.5cm (Case 2). The embankment was formed by fixing the height of 10cm and the slope of the slope at a ratio of 1:1.8. For seismic waves, excitation of a 5Hz sine wave was performed for 8 seconds, and a total of 5 case excitations were performed. In Case 1, it was confirmed that liquefaction occurred at all depths during the first vibration excitation at the free-field and that liquefaction did not occur at all depths except 5cm at the third vibration excitation. At the center of the embankment, liquefaction occurred up to a depth of 20cm during the first vibration excitation, and it was confirmed that liquefaction did not occur at all depths except for a depth of 5cm during the second vibration excitation.

• Journal of Biomedical Engineering Research
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• v.43 no.3
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• pp.136-146
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• 2022

In this study, it is intended to provide basic data that can help develop a cardiovascular simulator for performance evaluation of pulse wave detectors by identifying the development status of domestic and overseas cardiovascular simulators. A total of 119 papers were selected by excluding duplicate literature, gray literature, and literature not related to a cardiovascular simulator. Based on the selected literature, the research trend of cardiovascular simulators was analyzed. As a result of analyzing the purpose of the study, most of the simulators were developed to evaluate the hemodynamic properties of artificial hearts and valves. In addition, it was used for simulation evaluation or hemodynamic studies such as pulse wave studies. As a result of analyzing configurations of the simulators, a heart most often consisted of only one left ventricle. For blood vessels, the Windkessel model was most often constructed using chambers and valves. In most studies, blood was reproduced by mixing glycerin and water to reproduce both density and viscosity. In addition, as a result of analysis from the perspective of medical device performance evaluation, simulators for evaluating artificial heart and artificial valves have been studied a lot, whereas simulators for blood pressure, pulse wave, and blood flow devices have been relatively insignificant. Based on the review results, we suggested considerations when developing a simulator for performance evaluations of a pulse wave detector.