• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6242-6249
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• 2014

The aim of this study was to determine the physical performance and fear of falls in the community dwelling elderly and to investigate how the factors were connected to one another. The data was collected between January 3rd and March 30th, 2014 from 460 elderly people, aged 65 or older, who agreed to participate in this study. The data was sampled among the elders' assistants as a way of responding to the questionnaire after being read. The study scales were composed of the demographic characteristics, physical function and fear of falls. A total of 139 (30.2%) subjects had experienced a fall. The results showed a positive correlation with the chair rise, standing on the leg, pick up a penny from floor, timed up and go test, and fear of falls. Multiple linear regression analysis showed that a predictor of the fear of falls were chair rise and timed up and go test. A combination of physical performance accounted for 16.9% of the fear of fall. Based on the findings of this study, it is useful to more effectively develop fall prevention and intervention programs in a future study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4087-4094
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• 2010

The sensor data which is measured by Quadruped robot is utilized to recognize the physical environment or other information and to control the posture and walking of robot system. In order to control the robot precisely, high accuracy of sensor data is required, most of these sensors however, belongs to expensive and low-durable products. Moreover, these are exposed excessive load operation in a field condition if it is applied to field robot system. This issue becomes more serious one when the robot system is manufactured as a mass product. As in this context, this study suggests a virtual sensor technology to alternate or assist the main sensor system. This scheme is realized by using back-propagation algorithm of neural network theory, and the quality of estimated sensor data could be improved through the algorithmic and hardware based treatments. This study performs the various trial to identify the effective parameters which effect to the quality and reliability of estimated sensor data and tries to show the possibility of proposed methodology.

• PNF and Movement
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• v.17 no.1
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• pp.129-136
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• 2019

Purpose: This study is a comparison of spatiotemporal parameters between straight and curved walking in individuals with chronic hemiparetic stroke, investigating whether those patients can adapt their walking according to task demands and environmental changes. Methods: Twenty-eight patients who diagnosed with their first stroke at least six months prior to this study were recruited. They were measured for spatiotemporal parameters in three different walking conditions: straight walking, walking with an inner curve to the more-affected leg, and walking with an inner curve to the less-affected leg. This study also measured secondary clinical factors, such as the timed up-and-go test, the trunk impairment scale, and the dynamic gait index. The statistical methods for the three different walking conditions, using the averaged value of each condition, was repeated measures ANOVA. Results: The difference in cadence was statistically significant when comparing straight walking, walking with an inner curve to the more-affected leg, and walking with an inner curve to the less-affected leg. Swing duration (%) was also a statistically significant difference between straight walking and walking with an inner curve to the more-affected leg. However, differences in other spatiotemporal parameters were not statistically significant among the three conditions. Conclusion: The results of this study suggest that stroke survivors could adapt their walking according to straight and curved walking conditions, although cadence and swing duration were different between straight and curved walking groups.

• PNF and Movement
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• v.19 no.2
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• pp.261-267
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• 2021

Purpose: This study aimed to investigate changes in gait variables depending on whether a task was performed using a smartphone while walking on a ramp. Methods: The participants of this study were 41 college students attending U University located in Gyeongju City, Gyeongsangbuk-do. In this study, gait variables were measured during ramp gait while using a smartphone to perform a task and during ramp gait without performing such tasks. In other words, four walking conditions were used: 1) walking up a ramp, 2) walking up a ramp while using a smartphone to perform a task, 3) walking down a ramp, and 4) walking down a ramp while using a smart phone to perform a task. Gait variables were measured using a gait analysis tool (Legsys; BioSensics, USA), and stride time, stride length, stride velocity, cadence, and double support were analyzed. The order of measurements was randomized to control for order effects due to repeated measurements. Results: The comparative analysis of gait variables according to the presence or absence of smartphone use during ramp gait showed that there were significant differences in stride time, stride length, and stride velocity during both ramp ascent and ramp descent (p < 0.05). In both ramp ascent and ramp descent, stride time increased when walking using a smartphone, compared to when walking without using a smartphone (p < 0.05). However, in both ramp ascent and ramp descent, stride length and stride velocity were decreased when walking using a smartphone compared to when walking without using a smartphone (p < 0.05). Conclusion: The study results showed that the use of a smartphone during walking can affect safety. Therefore, it is necessary to improve the awareness of risks associated with walking while using a smartphone, and further research needs to be conducted in various environments and with different ramps.

• Journal of Biomedical Engineering Research
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• v.19 no.5
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• pp.519-530
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• 1998

In this paper, the basic study on the design of the flexible keel of the energy-storage prosthetic foot was performed in order to Improve the walking performance and Increase the activities of the below knee amputees. Based on the analysis of the anthropometric data and the normal gait on two dimensional sagittal plane available In the literature, we presented a model of the basic structure of the flexible keel of the prosthetic foot. The model of the basic structure was composed of the simple beams, and linear rotational spring and damper. Laminated carbon fiber-reinforced composites were selected as the material of the basic structure model of the flexible keel In order to apply the high strength and light weight materials to the basic structure of the flexible keel of the prosthetic foot. The recoverable strain energy In response to the change of beam shape was calculated bur the finite element analysis and it was suggested that the change of beam shape could be the design variable in flexible keel design. The simulation process was systematically designed by using orthogonal array table in order to design the flexible keel structure which could store the more recoverable strain energy. finite element analysis was carried but according to the design of simulations by using the finite element program ABAQUS and the flexible keel structure of the energy-storage prosthetic foot was obtained from the analysis of variance(ANOVA). The dynamic simulation model of the prosthetic walking using the flexible keel structure was made and the dynamic analysis was carried but during one walk cycle. Based on the above results, an effective design process was presented for the development of the prosthetic fool system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.18-35
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• 2020

Many human, roadway, and vehicle factors affect vehicle-pedestrian crashes. Especially, the roadway factors are easily defined and suitable for suggesting countermeasures. The characteristics of the road network are one of the roadway factors. The road network significantly influences behaviors and conflicts of drivers and pedestrians. A metropolitan city such as Seoul contains various types of road networks, and crash prevention strategy considering characteristics of the road network is required. In this study, we analyze the effects of road networks on vehicle-pedestrian crashes. In the study, high order road ratio, intersection ratio, high-low intersection ratio are considered as road network variables. Using Geographically Weighted Poisson Regression, crash frequencies in Dongs of Seoul are analyzed based on the road network variable as well as socioeconomic variables. As a result, Dongs are grouped by coefficient signs, and each group is suggested about improvement directions considering conflict situations.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.36-49
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• 2016

A subway system is one of the major transportation modes at a metropolitan area. When it meets the other lines, the metro station, so-called transferring station, is usually threatened by severe pedestrian congestion and safety issue of transit users including the transportation vulnerable. Although transportation planners forecast travel demand at the beginning, it is not easy to predict pedestrian flows precisely for a long term if land use plans have dramatically changed. Due to expensive costs, structural extension of metro stations is limited. Therefore, it requires efficient and technical improvements as meeting the demand of pedestrian and physical characteristics. In this study, the core mechanism of pedestrian movement-based simulation model was introduced and evacuation scenarios were analyzed with the developed model. As a result, the multiple optimal routes for unexpected events at the solid space of the multiple stories are easily searched through the simulator and in the case of Sadang Station, travel time can be reduced by 60% when the evacuation information and intuitive design are provided.

• Journal of Digital Convergence
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• v.17 no.6
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• pp.247-255
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• 2019

The purpose of this study is to compare kinesio tapping with transcutaneous electrical nerve stimulation to single intervention in chronic stroke patients. 29 stroke patients were divided into taping group (n = 10), transcutaneous electrical nerve stimulation group (n = 10), and taping with transcutaneous electrical nerve stimulation group (combined group n = 9). The intervention period was 5 times (30min) per week for 4 weeks. Timed Up & Go (TUG) and Berg Balance Scale (BBS) were used for balance evaluation. Functional Gait Assessment (FGA) and 10-meter walk test were used for gait evaluation. The quality of life evaluation was performed using the EuroQol-5 dimension (EQ-5D). There were significant improvements in TUG, BBS, FGA, 10-meter walk test, and EQ-5D in all three groups (p <.05). In the comparison of the intervention effects between the three groups, the combined group showed a significant increase in FGA compared to the other two groups. This study showed that taping with transcutaneous electrical nerve stimulation is more effective for FGA than single methods. However, there was no difference between the three groups except for FGA. Therefore, more subjects and intervention period will be needed in future studies.

• Tuberculosis and Respiratory Diseases
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• v.64 no.6
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• pp.433-438
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• 2008

Background: Measurement of the maximum oxygen uptake in patients with chronic obstructive pulmonary disease (COPD) has been used to determine the intensity of exercise and to estimate the patient's response to treatment during pulmonary rehabilitation. However, cardiopulmonary exercise testing is not widely available in Korea. The 6-minute walk test (6MWT) is a simple method of measuring the exercise capacity of a patient. It also provides high reliability data and it reflects the fluctuation in one' s exercise capacity relatively well with using the standardized protocol. The prime objective of the present study is to develop a regression equation for estimating the peak oxygen uptake ($VO_2$) for men with moderate to very severe COPD from the results of a 6MWT. Methods: A total of 33 male patients with moderate to very severe COPD agreed to participate in this study. Pulmonary function testing, cardiopulmonary exercise testing and a 6MWT were performed on their first visits. The index of work ($6M_{work}$, 6-minute walk distance [6MWD]${\times}$body weight) was calculated for each patient. Those variables that were closely related to the peak $VO_2$ were identified through correlation analysis. With including such variables, the equation to predict the peak $VO_2$ was generated by the multiple linear regression method. Results: The peak $VO_2$ averaged $1,015{\pm}392ml/min$, and the mean 6MWD was $516{\pm}195$ meters. The $6M_{work}$ (r=.597) was better correlated to the peak $VO_2$ than the 6MWD (r=.415). The other variables highly correlated with the peak $VO_2$ were the $FEV_1$ (r=.742), DLco (r=.734) and FVC (r=.679). The derived prediction equation was $VO_2$ (ml/min)=($274.306{\times}FEV_1$)+($36.242{\times}DLco$)+($0.007{\times}6M_{work}$)-84.867. Conclusion: Under the circumstances when measurement of the peak $VO_2$ is not possible, we consider the 6MWT to be a simple alternative to measuring the peak $VO_2$. Of course, it is necessary to perform a trial on much larger scale to validate our prediction equation.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.1-8
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• 2010

The optimum forest road density was calculated with the method which is used in Europe on the investigation site in Korea. The economical optimum forest road density at the minimum total transport cost was 10.51 m/ha. The total transport cost was calculated 235,354 won/ha per year. The forest road construction cost amounted to 99,693 won/ha per year in case of the depreciation period of 30 years and the interest rate of 3%, the forest road maintenance cost amounted to 14,502 won/ha per year, the logging cost amounted to 99,564 won/ha per year, the cost of footpaths amounted to 18,142 won/ha per year, the cost by the loss of the production area amounted to 3,454 won/ha per year.