• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.113-121
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• 2013

An expansion into the global market increasingly becomes a buzz world among Construction Management(CM) firms in Korea. The objective of this study is to identify potential obstacles and investigate their nature and implications to CM firms in Korea. The study identified 25 obstacles under 5 categories. Base on a questionnaire survey and interviews with CM experts who have global CM projects experience, the study discusses that while there exist various types of obstacles, a more attention needs to be paid for a small number of major obstacles to minimine risks in overseas CM projects. It also suggests that improving pre-construction management competency through securing CM experts should be listed as a top agenda for Korean CM firms.

• The Journal of Korean Physical Therapy
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• v.23 no.6
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• pp.15-22
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• 2011

Purpose: This research investigated falls due to obstacles that occur among elderly people by assessing changes in the values of plantar foot force, peak force, and plantar foot pressure in elderly subjects while they were stepping over obstacles of different heights. Methods: The subjects were 20 elderly people aged 70-80 years; Pressure was measured on flat ground(0 cm), and after installing obstacles of 8 cm and 12 cm using the F-scan system, which is a resistance-type pressure sensor. A one-way analysis of variance was performed to compare pressure on each part of the foot according to various heights after collecting data using the Tekscan program. The least significant difference test was used for the post-hoc analysis, A p-value <0.05 was considered significant. Results: The force value for the toe area (parts 1, and 2) and contact pressure increased significantly with the 12 cm obstacle (p<0.05). The peak force value and the peak contact pressure for part 1 increased significantly with the 12 cm obstacle (p<0.05). Conclusion: Larger changes appeared in the functions and structure of the foot while subjects walked over obstacles of different heights compared to flatland walking. This result suggests that people have safety strategies to prevent falls, and that there is a need for a more realistic approach through practice to overcome obstacles of various heights to prevent falls.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.4
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• pp.55-62
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• 2019

PURPOSE: This study examined the muscle activity while stepping over obstacles with various heights and widths to provide basic data for training and preventing falls. METHODS: Fifteen normal young adults (seven males and eight females) were recruited. The participants walked on a 5m walkway with six obstacles. The heights of obstacles were 0%, 10%, and 40% of the subject's leg length, and the width of the obstacles was 7cm and 14cm. The participants traversed the course twice per obstacle. The muscle activities of the soleus, tibialis anterior (TA), vastus medialis (VM), and vastus lateralis (VL) were measured using surface electromyography. A Mann-Whitney test and Kruskal-Wallis test were used to examine the differences between obstacles. RESULTS: The muscle activities of the VL and the soleus of the stance leg and lead leg after crossing over the obstacles increased with increasing width, and there were significant differences in muscle activities between obstacle width (p<.05) except for the muscle activity of TA of the stance leg after crossing over the obstacles. A significant difference in muscle activities was observed according to the height of the obstacles with 14 cm (p<.05) except for the muscle activity of the VL, soleus of the leading leg, and TA of the stance leg CONCLUSION: The role of the VL and Soleus increased with increasing obstacle width, and the overall muscle activities of the lower extremities increased with increasing obstacle height. These results can be used to suggest a program to prevent falls.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.463-466
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• 2004

This paper describes an image processing algorithm for recognition of small-obstacles using a camera and program for a mobile robot in indoor environment. Mobile robot could meet small-obstacles such as a small plastic bottle of about 1l in quantity, a small box of 7$\times$7$\times$7 cm$^3$ in volume, and so on in its designated path, and could be disturbed by them in the locomotion of a mobile robot. So, it is necessary to research on the image processing algorithm for recognition of small-obstacles using a camera and program. In this paper, 2-D the image processing algorithm for recognition of small-obstacles using a camera and program for a mobile robot in indoor environment was developed. The characteristic test of the developed program to confirm the recognition of small-obstacles was performed. It is shown that the developed program could recognize small-obstacles accurately.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.3
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• pp.85-91
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• 2017

PURPOSE: The purpose of this study was to compare muscle activation of the trunk and lower limbs of subjects wearing high-heeled or flat shoes while crossing over obstacles of different heights. METHODS: Twenty subjects participated in this study. While wearing high-heeled shoes (7 cm) or flat shoes (0 cm), the subjects were asked to cross over obstacles of different heights (10%, 20%, and 30% of their lower-limb length). Muscle activation of the trunk and lower limbs with the supported side while crossing over obstacles of different heights was measured using the electromyogram (Noraxon, DTS, Germany). Two-way repeated ANOVA was used to compare the muscle activation between high-heel shoes and flat shoes while crossing over obstacles of different heights. All statistical analyses were performed using SPSS ver. 21, and p-values less than .05 were used to identify significant differences. RESULTS: As an obstacle's height increased, muscle activation of the trunk and lower limbs with the supported side was increased while wearing either type of shoe, and it was generally higher while wearing high-heeled shoes. However, tibialis anterior muscle activity while wearing high-heeled shoes was lower than while wearing flat shoes. CONCLUSION: This study showed that muscle activation of the trunk and lower limbs was higher when subjects wore high-heeled shoes than when they wore flat shoes while crossing over obstacles of different heights. Therefore, high-heeled shoes can easily cause high muscle fatigue of the trunk and lower limbs, and the TA muscle may weaken in persons who wear high-heeled shoes.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.85-92
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• 2005

This paper describes the recognition method of small-obstacles using a camera for a mobile robot in indoor environment. The technique of image processing using a camera has been widely used for an automaton of industrial system, an inspection of inferior goods, a lookout of an invader, and a vision sensor of intelligent robot. Mobile robot could meet small-obstacles such as a small plastic bottle of about 0.5 l in quantity, a small box of $7{\times}7{\times}7cm^3$ in volume, and so on in its designated path, and could be disturbed by them in the locomotion of a mobile robot. So, it is necessary to research on the recognition of small-obstacles using a camera and program. In this paper, 2-D image processing algorism and method fur recognition of small-obstacles using a camera for a mobile robot in indoor environment was developed. The characteristic test of the developed program to confirm the recognition of small-obstacles was performed. It is shown that the developed program could judge the size and the position of small-obstacles accurately.

• The Journal of Korean Physical Therapy
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• v.21 no.3
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• pp.75-80
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• 2009

Purpose: The purpose of this study was to examine the effect of an obstacle height on the balance control of older adults while stepping over an obstacle from a position of quiet stance. Methods: Fifteen community-dwelling healthy older adults (mean age, $74.4\pm4.27$ yrs; age range, 67-82 yrs) volunteered to participate in this study. The subjects performed gait initiation (GI) and they stepped over obstacles of two different heights (10 cm and 18 cm) at a self-paced speed from a position of quiet stance. Their performance was assessed by recording the changes in the displacement of the COP in the anteroposterior (A-P) and mediolateral (M-L) directions using a force platform. Results: The M-L displacement of the COP significantly increased for an 18 cm obstacle height condition as compared to the GI and a 10 cm obstacle height condition (p<0.01). Furthermore, the M-L displacement of the COP for a 10 cm high obstacle was significantly greater for that for the GI (p<0.01). However, the mean of the A-P displacement of the COP was similar between the stepping conditions for the A-P displacement of the COP (p>0.05). Conclusion: This study suggests that the M-L COP displacement could be a better parameter to identify the dynamic balance control in older adults when negotiating obstacles.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.487-490
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• 2007

Even though the domestic CM market has expanded in size continually since 2000, concerns of obstacles for vitalizing CM market have risen. A critical concern is clients' low recognition and motivation to make use of CM services. In this situation, it is important for CM firms to actively promote their marketing activities. The objective of this paper is to identify major characteristics of CM firms' marketing strategies and methods in relation to the management of CM service as a commodity.

• Journal of Biosystems Engineering
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• v.23 no.2
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• pp.179-186
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• 1998

This study was conducted to sense posture of an autonomous tractor using a DGPS, a gyro compass, and a potentiometer. Posture sensing system was constructed and its accuracy was evaluated. The accuracy of DGPS was evaluated under stationary and moving conditions, and the performance of the gyro compass and the potentiometer was investigated by measuring bearing and steering angles, respectively. Also, the effect of DGPS interference by obstacles was evaluated experimentally. The position accuracy was about 6.6cm(95%) under the stationary condition and 10 cm at sharp turning condition. Steering angle of the tractor could be related linearly to the output of the potentiometer that was installed on the rotating center of a knuckle arm. The positioning accuracy of the DGPS varied significantly according to the number of visible GPS satellites, but was good with more than 7 satellites. The DGPS gave bad solutions for sensing the posture of tractor when signals from satellites or the correction data from the base were interfered by obstacles.

• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.11-17
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• 2008

Falls associated with tripping over an obstacle can be dangerous, yet little is known about the strategies used for stepping over obstacles by Parkinson's patients. The purpose of this study was to investigate stepping over gait characteristics according to obstacle height in Parkinson's patients. The gait of 7 Parkinson's patients was examined during a 5.0 m approach to, and while stepping over, obstacles of 0, 2.5, 5.2, and 15.2 cm. Only five Parkinson's patients were able to clear all obstacles successfully; as such, only their data were analyzed. A one-way ANOVA for repeated measures was employed for selected kinematic variables to analyze the differences of the height of four obstacles. The results showed significant differences between obstacle height and: approaching speed (AS), foot clearance from the obstacle(FC), and step width (SW). The results showed no significant differences between obstacle height and: crossing speed (CS), toe distance (TD), and heel distance (HD). This strategy tends to reduce the risk of toe contact with the obstacle. Parkinson's patients were stepping over the obstacle slowly, stably and inefficiently.