• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.681-686
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• 2010

Although the height of a ramp is an important design element, it has not been considered in prior studies. Therefore, in this study, the ramp slope and height are considered as independent variables. To analyze the effects of the slope and height, five levels of slope (1:6, 1:8, 1:10, 1:12 and 1:14) and three levels of height (15cm, 30cm and 45cm) are considered. For the dependent variables, the total time, velocity and perceived discomfort were considered as usability measures, pulse rate changes and EMG signals of four related muscles (extensor carpi radialis, triceps brachii, anterior deltoid and posterior deltoid) were considered as physiology measures. As a result, differences among usability and physiological characteristic for the five slopes increased as the height increased. Additionally, slope effects were minor when the height was low (15cm). Almost domestic/international regulations and guidelines related to ramp recommended 1:12 slope for the ramp design, however, there was no significant difference between 1:10 and 1:12 according to result of this study. In addition, slope effects were minor at a low height; thus, a slope of 1:8 can be recommended if the installation space for a gentler ramp is not sufficient.

• Korean Institute of Interior Design Journal
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• v.19 no.2
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• pp.3-14
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• 2010

As the seniors and the disabled has increased, the demand for cultural centers has also increased in many local areas. This means that the local cultural centers designed from the viewpoint of universal design are needed, so that to be used by everyone without any difficulties. This study examined the applicability of universal design principles to the public service areas of the local cultural centers. The subject cultural centers were three local ones which had seating capacity of more than 1,000 and opened after the year of 2,000 in Gyungnam. The spatial scopes of the study were six public service areas of the local cultural centers : entrance area, corridor and pathway, stair, ramp, elevator, and rest room. The total 65 items for evaluating the applicability of universal design were selected and examined for six areas. On the whole, accessibility, such as wide pathway and flat floor was good. However, the following improvements were needed. 1) Handrails and rounded corner were needed on walls. 2) Consideration of the visually impaired like as braille sign was needed. 3) The handrails on ramp should be installed for usability. 4) The automatic door would be more useful to the physically disabled users. 5) Wider space and familiar handrail design and color were needed in the rest rooms for the handicapped.

• Korean Institute of Interior Design Journal
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• no.12
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• pp.25-32
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• 1997

The fast growth of the elderly population and nuclear families have been creating substantial needs for residential facilities of aged people in Korea. In this study, reviews on housing preference and physical constraints have been performed based on previous researches. In this study, the results of the analyses propose developmental strategies for the elderly housing in Korea as follows: 1)Housing preference and other psychological trends of Korean elderly are rooted in changeable condition of the emotion and lack of knowledge. Therefore, the housing preference of the Korean elderly should not be considered a fixed reflection ; rather, it should be regarded as a continuously adjusted trends according to later experience and emotional status after residing in the elderly care facilities. 2)Design of elderly housing should be guided within two principles of easy access and high usability. The principles also require maximazation of social interactions among frail elderly residents on age-segregated structure. 3) The experiment among 201 frail elderly shows that each shower stall should accommodate 5-by-5 feet square for wheelchair u-turn, and 48 inch height for kitchen topsink. Finally, the experiment shows that ramp slope of the ederly housing should be within 1/16 and 1/20.

• Journal of the Ergonomics Society of Korea
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• v.33 no.6
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• pp.487-497
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• 2014

Objective: This study aims to develop and evaluate a multi-purpose rollator, which may be used as a seat, as a traditional walker, or as a storage basket for elderly farmers. Background: The rollators on the market are not user-friendly designed and seen inconvenient for elderly farmers to use, although they are sold at considerably high price. Since they lack enough space to load stuffs and are not durable or stable enough, they do not seem to be suitable for elderly farmers to use in rural areas. Method: Two types of methods were used in this study. First, the survey consisted of 19 questions was conducted among elderly farmers in rural areas, after using the developed rollator, to evaluate the usability of the rollator developed in this study. Second, EMG experiment was conducted to compare the existing rollator and developed rollator quantitatively. Through this experiment, we tried to verify the differences of muscle responses, when using the traditional and the developed ones, which have their own brake system, in the ramp. Results: The developed rollator was highly evaluated in most of the questions in the usability survey, except for the 'Weight' category in which the opinions were divided into three different types (Worse: 31%, Similar: 30%, Better: 36%). The result of EMG experiment showed that the existing rollator (7.4%MVC) demands more muscle strength than the developed rollator (5.5%MVC) does. By statistically analyzing the results of upper limb and lower limb respectively, we found out that all the muscles except deltoid in upper limb showed statistically significant differences in muscle activity when using the existing and the developed rollator. However, there was no statistical difference in lower limb muscles. Conclusion: The developed rollator in this study has maximized the functionality of the brake system, the storage and the chair, which were pointed out as the weaknesses of existing rollators. Furthermore, the developed rollator is designed to be more user-friendly, safe, durable, and effective for elderly farmers to use in rural areas, where roads are rough and bumpy. Application: We expect that the emergency brake system developed in this study would be utilized for other convenience equipment, such as strollers and carts, and that it would be able to develop and produce more secure and reliable equipment in the future.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.12
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• pp.1340-1345
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• 2012

Industrial products developed in recent years have focused on usability and stability. Especially, for the products used in daily life, steady efforts have been made to secure the safety. Among them, the products equipped with wheels such as strollers, shopping carts, and carriers can occur the safety accidents by unintended over speed at a ramp. Therefore, development of speed limit device is required to prevent such accidents. However, the existing speed limit devices are very expensive and have a complex drive principle, so it's generally difficult to apply them. In this study, a simple speed limit wheel is suggested which can replace the previous complex and inconvenient speed limit devices. The developed speed limit wheel can be simply applied to existing products by changing the wheels. In addition, it has an advantage to operate only by mechanical mechanism without power supply. Thus it can minimize the cost and waste of resources. For this purpose, the operating condition of the target products was analyzed, and trochoid gear mechanisms were selected for the speed limit. Based on this, finite element analysis was conducted to estimate the operating mechanism. After the prototype of the wheel was produced, the performance under various conditions was tested and has been improved.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1731-1741
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• 2014

Recently, many overpasses, highway, and advanced transit systems have been constructed to distribute the traffic congestion, thus small size of curved bridges with small curvature such as ramp structures have been increasing. Many of early curved bridges had been constructed by using straight beams with curved slabs, but curved steel beams have replaced them due to the cost, aesthetic and the advantage in building the section form and manipulating the curvature of beams, thereby large portion of curved bridges were applied with steel box girders. However, steel box girder bridges needs comparatively high initial costs and continuous maintenance such as repainting, which is the one of the reason for increasing the cost. Moreover, I-type steel plate girder which is being studied by many researchers recently, seem to have problems in stability due to the low torsional stiffness, resulting from the section characteristics with thin plate used for web and open section forms. Therefore, in recent studies, researchers have proposed curved precast PSC girders with low cost and could secured safety which could replace the curved steel girder type bridges. Hence, this study developed a Smart Mold system to manufacture efficient curved precast PSC girders. And by using this mold system a 40 m 2-girder bridge was constructed for a static flexural test, to evaluate the safety and performance under ultimate load. At the manufacturing stage, each single girder showed problems in the stability due to the torsional moment, but after the girders were connected by cross beams and decks, the bridge successfully distributed the stress, thereby the stability was confirmed. The static loading test results show that the initial crack was observed at 1,400 kN when the design load was 450 kN, and the load at the allowable deflection by code was 1,800 kN, which shows that the safety and usability of the curved precast PSC bridge manufactured by Smart Mold system is secured.