• Journal of Drive and Control
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• v.15 no.3
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• pp.1-7
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• 2018

Humanoid robots have fascinated many researchers since they appeared decades ago. For the requirement of both accurate tracking control and the safety of physical human-robot interaction, torque control is basically desirable for humanoid robots. Humanoid robots are highly nonlinear, coupled, complex systems, accordingly the calculation of robot model is difficult and even impossible if precise model of the humanoid robots are unknown. Therefore, it is difficult to control using traditional model-based techniques. To realize model-free torque control, time-delay control (TDC) for humanoid robot was proposed with time-delay estimation technique. Using optimal walking trajectory obtained by particle swarm optimization, TDC with proposed scheme is implemented on whole body of a humanoid, not on biped legs even though it is performed by a virtual humanoid robot. The simulation results show the validity of the proposed TDC for humanoid robots.

• Steel and Composite Structures
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• v.30 no.6
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• pp.577-589
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• 2019

In this study, on-site testing was carried out to investigate the vibration performance of a composite steel-bar truss slab with steel girder system. Ambient vibration was performed to capture the primary vibration parameters (natural frequencies, damping ratios, and mode shapes). The composite floor possesses low frequency (< 10 Hz) and damping (< 2%). Based on experimental, theoretical, and numerical analyses on natural frequencies and mode shapes, the boundary condition of SCSC (i.e., two opposite edges simply-supported and the other two edges clamped) is deemed more reasonable for the composite floor. Walking excitations by one person (single excitation), two persons (dual excitation), and three persons (triple excitation) were considered to evaluate the vibration serviceability of the composite floor. The measured acceleration results show a satisfactory vibration perceptibility. For design convenience and safety, a crest factor ${\beta}_{rp}$ describing the ratio of peak acceleration to root-mean-square acceleration induced from the walking excitations is proposed. The comparisons of the modal parameters determined by ambient vibration and walking tests reveal the interaction effect between the human excitation and the composite floor.

• Journal of Korea Multimedia Society
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• v.22 no.1
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• pp.62-69
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• 2019

In this paper, we propose iZone system for safe walking of children. The proposed system recognizes the state that a child is down a roadway as a dangerous situation. And then it informs the surrounding adults and guardians of the child in the event of a dangerous situation. The iZone system consists of the iZone device that attaches to a child's bag or clothing, the iZone app for children, the iZone server, and external beacons. The proposed system uses the ultrasonic sensor of the iZone device and the GPS coordinates and external beacons information by the children's smartphone to determine the dangerous situation. The proposed system uses external beacons to calibrate the GPS coordinates. Moreover, it determines whether the child is down the roadway in sidewalk by measuring the height difference between the roadway and the sidewalk using ultrasonic sensor.

• 한국도로학회:학술대회논문집
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• 2009.11a
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• pp.421-426
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• 2009

• The Journal of the Korea Contents Association
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• v.20 no.10
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• pp.190-198
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• 2020

The development in smartphone technology has brought convenience to the life of the mankind, but an excessive use of smartphones sometimes causes various accidents. This research tried to propose an application service 'Smombie Safe Go' UI(User Interface) that allows the prevention of such accident while using smartphones when walking. For this, after research and user observations, produced walker journey maps and derived necessary main functions needed for safety, and the result showed that transparent interface, obstacle location alert, warning of dangers functions were necessary. To make the contents of the service more detailed, hazardous situations faced during smartphone use when walking were classified into 3 situations : 1. Obstacle appearing in front, 2. traffic lights on crosswalks 3. No traffic lights on crosswalks. Scenarios by hazardous situation were written, and the flow and UI of the app service that warns its users in each situation of hazards were designed. it is predicted that 'Smombie Safe Go' may be possible to be utilized as an app service that provides a safe walking experience for not only regular pedestrians but also the blind population.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.1
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• pp.71-81
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• 2018

The purpose of this study is to develop neighborhood assessment tools from the perspective of women in order to evaluate neighborhood environments and suggest better policies and planning practices for women-friendly neighborhood environments. To do so, we analyze correlations between women's quality of life and the neighborhood environment. Specifically, we gave female participants a mapping survey, interview, and questionnaire to collect data targeting women living in Onyang 2-dong and 5-dong in Asan city. First, we developed a neighborhood assessment tool derived from an extensive literature review and particular case studies. The mapping and interview surveys indicated that specific aspects neighborhood life needed to be improved in a similar area. In particular, women complained about Onyangoncheon station, a commercial area, and detached house area. Second, analysis of the neighborhood environmental factors affecting women's neighborhood satisfaction, crime safety, traffic and walking environment, accessibility of living facilities, green and public spaces and childcare environment were statistically significant. Of these, the inclusion of green and public spaces was the most influential factor. Third, the neighborhood environmental factors affecting women's neighborhood attachment, crime safety, traffic and walking environment, accessibility of living facilities, green and public spaces and childcare environment were statistically significant. Of these, accessibility of living facilities appeared to be the most influential factor. Fourth, the neighborhood environmental factors affecting women's housing mobility decisions, crime safety, traffic and walking environment, accessibility of living facilities, green and public spaces and childcare environment were statistically significant. Of these, childcare environment was the most influential factor.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.1
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• pp.65-74
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• 2021

This study empirically analyzes the effect of pedestrians' personal and household characteristics and accessibility to public facilities on a walking safety satisfaction (WSS) level. The aim is to find ways to improve vulnerable pedestrians' WSS level and contribute to the creation of an inclusive urban environment. As a result of the analysis, age and gender variables were important for elderly people, and education was an important factor for disabled people. The WSS level was impacted by the factors of single-person households, income, and residential areas. In the case of accessibility to public facilities, the greater the satisfaction with accessibility to public institutions, urban parks and green areas, and public transport, the greater the WSS for the elderly and the disabled. And, the greater the satisfaction with accessibility to commercial facilities, the greater the WSS was for the elderly's WSS. However, the satisfaction with access to medical facilities was the opposite in the case of the elderly.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.87-95
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• 2023

On October 29, 2022, a very large number of people gathered in Itaewondong, Yongsan-gu, Seoul, Korea for a Halloween festival, and as crowds pushed through narrow alleys, 159 deaths and 195 injuries occurred, making it the largest crushing incident in Korea. There have been a number of stampede deaths where crowds gathered at large-scale festivals, event venues, and stadiums, both at home and abroad. When the density increases, the physical contact between bodies becomes very strong, and crowd turbulence occurs when the force of the crowd is suddenly added from one body to another; thus, the force is amplified and causes the crowd to behave like a mass of fluid. When crowd turbulence occurs, people cannot control themselves and are pushed into he crowd. To prevent a stampede accident, investigation and management of areas expected to be crowded and congested must be systematically conducted, and related ministries and local governments are planning to establish a crowd management system to prepare safety management measures to prevent accidents involving multiple crowds. In this study, based on national data, a continuous digital topographic map is modeled in 3D to analyze the risk of crowding and present a plan for selecting high-risk walking routes. Areas with a high risk of crowding are selected in advance based on various data (numerical data, floating population, and regional data) in a realistic and feasible way, and the analysis is based on the visible results from 3D modeling of the risk area. The study demonstrates that it is possible to prepare measures to prevent cluster accidents that can reflect the characteristics of the region.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.169-175
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• 2000

Stable and comfortable walking supports, which can reduce the body weight load partially, are needed for the recovering patients from neurologic disease and orthopedic procedures. In this paper, the development of a manipulator of rehabilitation robot for the patients with walking disabilities are studied. A force controller using pneumatic actuators is designed and implemented to the human friendly rehabilitation robot considering the safety of patients, reliability of the system, effectiveness of the unloading control and economic maintenance of the system. The mechanism of the unloading manipulator is devised to improve the sensibility for the movement of the patients such as direction and velocity. For the unloading force control, fuzzy control algorithm is adopted to reduce the partial body weight and suppress the unwanted fluctuation of the body weight load to the weak legs due to the unnatural working of the patients with walking disabilities. The effectiveness of the force control is experimentally demonstrated.

• Structural Engineering and Mechanics
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• v.74 no.5
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• pp.711-722
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• 2020

In this study, on-site testing was carried out to investigate the vibration serviceability of a composite steel-bar truss slab with steel girder system. Impulse excitations (heel-drop and jumping) and steady-state motion (walking and running) were performed to capture the primary vibration parameters (natural frequency and damping ratio) and distribution of peak acceleration. The composite floor possesses low frequency (<8.3Hz) and damping ratio (<2.47%). Based on experimental, theoretical, and numerical analyses on fundamental natural frequency, the boundary condition of SCSS (i.e., three edges simply supported and one edge clamped) is deemed more comparable substitutive for the investigated composite floor. Walking and running excitations by one person (single excitation) were considered to evaluate the vibration serviceability of the composite floor. The measured acceleration results show a satisfactory vibration perceptibility. For design convenience and safety, a crest factor β_rp describing the ratio of peak acceleration to root-mean-square acceleration induced from the walking and running excitations is proposed. The comparisons of the modal parameters determined by walking and running tests reveal the interaction effect between the human excitation and the composite floor.