• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.632-637
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• 2017

Even though the potential for an accident in nuclear power plants is very low, multiple emergency plans are necessary because the impact of such an accident to the public is enormous. One of these emergency plans involves a robotic system for investigating accidents under conditions of high radiation and contaminated air. To develop a robot suitable for operation in a nuclear power plant, we focused on eliminating the three major obstacles that challenge robots in such conditions: the disconnection of radio communication, falling on uneven floors, and loss of localization. To solve the radio problem, a Wi-Fi extender was used in radio shadow areas. To reinforce the walking, we developed two- and four-leg convertible walking, a floor adaptive foot, a roly-poly defensive falling design, and automatic standing recovery after falling methods were developed. To allow the robot to determine its location in the containment building, a bar code landmark reading method was chosen. When a severe accident occurs, this robot will be useful for accident condition monitoring. We also anticipate the robot can serve as a workman aid in a high radiation area during normal operations.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.1174-1176
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• 2011

Unfortunately, the number of blind people increases every 5 seconds in our world. An extensive research was made on improving the conventional walking cane and developing a microcontroller based walking stick for the blind with sensors and a feedback in form of vibration. Two different kinds of sensors are used to detect obstacles, ultrasonic and infrared distance sensors. The signal from an ultrasonic sensor is fed to a microcontroller. With the help of the supporting software, the Pulse Width Modulation (PWM) principle is extensively used to form three zones and run the corresponding vibration motor at different spends according to how far the detected object is located. The other infrared distance sensors are connected to amplifiers and after that to their corresponding vibration motors through motor drivers. The vibration motors are to be located around the user's arm to notify the blind of the obstacles in the intended walking way. It can be very reliable and sufficient device guiding the blind other than the conventional walking cane which has many drawbacks which will be explained and discussed.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.80-88
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• 2017

Although hazard identification is one of the most important steps of safety management process, numerous hazards remain unidentified in the construction workplace due to the dynamic environment of the construction site and the lack of available resource for visual inspection. To this end, our previous study proposed the collective sensing approach for safety hazard identification and showed the feasibility of identifying hazards by capturing collective abnormalities in workers' walking patterns. However, workers generally performed different activities during the construction task in the workplace. Thereby, an additional process that can identify the worker's walking activity is necessary to utilize the proposed hazard identification approach in real world settings. In this context, this study investigated the feasibility of identifying walking activities during construction task using Wearable Inertial Measurement Units (WIMU) attached to the worker's ankle. This study simulated the indoor masonry work for data collection and investigated the classification performance with three different machine learning algorithms (i.e., Decision Tree, Neural Network, and Support Vector Machine). The analysis results showed the feasibility of identifying worker's activities including walking activity using an ankle-attached WIMU. Moreover, the finding of this study will help to enhance the performance of activity recognition and hazard identification in construction.

• Fire Science and Engineering
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• v.25 no.1
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• pp.72-77
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• 2011

The effort of transferring some parts of urban functions to the underground space is growing trend among modem cities because of the limit of horizontal land use, the rise of land value, the diversification of human desire, etc. Thus, the basement of building and the subway station have deepened. It calls our attention to safety about evacuation from the underground space to the ground. Until now, the study about crowding walk in stairs has been progressed, focusing on the crowding walk that is going down the stairs, and there is no study about crowding walk that is going up the stairs. This study measured walking pace by crowd density that is going up the stairs in the subway station stairs making one-way movement of crowd. The actual survey showed that the mathematical relation 'V=0.638-0.0949p' determines going up walking velocity at a gradient of $23^{\circ}$, and the mathematical relation will be 'V=0.597-0.1067p' at a gradient of $30^{\circ}$, when it is converted, based on the average walking velocity of crowd by the slope of the stairs which is recommended by Architectural Institute of Japan.

• Korean Journal of Adult Nursing
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• v.23 no.4
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• pp.412-419
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• 2011

Purpose: The purpose of this study was to investigate the effects of a walking and resistance exercise on body composition and lipid profile in obese women. Methods: Fourty three women were assigned to experimental group (n=21) or control group (n=22). The walking and resistance exercise using elastic band was provided three times a week for 12 weeks. Weight, height, body mass index, body fat percentage, abdominal fatness, skeletal muscle mass, body fatness, total cholesterol, triglyceride, HDL cholesterol, and LDL cholesterol were measured before and after the program. Paired and independent t-tests were performed using SAS program. Results: Weight (t=-5.35, p<.001), body mass index (t=-4.12, p<.001), body fat percentage (t=-2.33, p =.026), and body fatness (t=-4.32, p<.001) were significantly decreased and skeletal muscle mass (t=2.09, p =.044) was significantly increased after the walking and resistance exercise. Also, total cholesterol (t=-3.03, p =.006) and LDL cholesterol (t=-2.70, p =.011) were significantly decreased and HDL cholesterol (t=2.05, p =.046) was significantly increased after the exercise program. Conclusion: According to the study result, exercise led a positive outcome on obese women in their 30~40s. The walking and resistance exercise will contribute to the improving body composition and lipid profile in this population.

• Journal of Korea Multimedia Society
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• v.11 no.12
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• pp.1676-1687
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• 2008

In this paper, we proposed a new multi-view human recognition method based on face and gait features detection algorithm. For getting the position of moving object, we used the different of two consecutive frames. And then, base on the extracted object, the first important characteristic, walking direction, will be determined by using the contour of head and shoulder region. If this individual appears in camera with frontal direction, we will use the face features for recognition. The face detection technique is based on the combination of skin color and Haar-like feature whereas eigen-images and PCA are used in the recognition stage. In the other case, if the walking direction is frontal view, gait features will be used. To evaluate the effect of this proposed and compare with another method, we also present some simulation results which are performed in indoor and outdoor environment. Experimental result shows that the proposed algorithm has better recognition efficiency than the conventional sing]e view recognition method.

• Journal of Korean Society of Transportation
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• v.35 no.5
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• pp.396-408
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• 2017

In Korea, the number of elderly has been increasing rapidly. So it is also expected that the economic activity and the trip frequency of the elderly will increase. On the other hand, elderly related accidents such as falls during walking are steadily increasing and the satisfaction about pedestrian environment of elderly is very low. In this paper, we found one of the reasons for these dissatisfaction in pedestrian facility, which is not considering the walking ability (about 75% of non-elderly person) of the elderly. So, we analyze the kinematic walking characteristics of the elderly with the motion analysis system, when the elderly use stairs. As a result of analysis of various walking variables, the current standard for stairway height in Korean law (18cm) requires excessive force to elderly so it was difficult for elderly to keep the balance of the body in ascending and descending walk of stairs. In this paper, we propose the stair design criteria through the cluster analysis of walking parameters reflecting the gait characteristics of the elderly. This change is not a big for non-elderly person, but it can promote more socioeconomic activities for the elderly.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.489-498
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• 2015

Objective : The purpose of this study was to analyze the effects of the windlass mechanism in trail-walking shoe prototypes that can effectively support arches. A study of these effects should help with the development of a first-rate trail-walking shoe development guide for the distribution of quality information to consumers. Methods : The subjects were ten adult males who volunteered to participate in the study. Shoes from three companies, which will be referred to as Company S (Type A), Company M (Type B), and Company P (Type C), were selected for the experiment. The subjects wore these shoes and walked at a speed of 4.2 km/h, and as they tested each shoe, the contact area, maximum pressure average, and surface force were all measured. Results : Shoe Type A showed a contact area of $148.78{\pm}4.31cm^2$, Type B showed an area of $145.74{\pm}4.1cm^2$, and Type C showed an area of $143.37{\pm}4.57cm^2$ (p<.01). Shoe Type A demonstrated a maximum average pressure of $80.80{\pm}9.92kPa$, Type B an average of $85.72{\pm}11.01kPa$, and Type C an average of $89.12{\pm}10.88bkPa$ (p<.05). Shoe Type A showed a ground reaction force of $1.13{\pm}0.06%BW$, Type B a force of $1.16{\pm}0.04%BW$, and Type C a force of $1.16{\pm}0.03%BW$ (p<.05). Conclusion : The Type A trail-walking shoe, which was designed with a wide arch from the center of the forefoot to the front of the rearfoot showed excellent performance, however, more development and analysis of the windlass mechanism for a variety of arch structures is still necessary.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.3
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• pp.31-38
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• 2020

In this paper, we compare and analyze smart technologies and present six obstacle detection features to help visually impaired people walk. Traditionally, visually impaired people walk with the white cane or a guide dog. With the development of IoT technology, various smart walking aids systems have been developed. Those intelligent walking aids systems have obstacle-detecting systems and route-guidance systems. Many researchers are developing the walking aids system, which detects an obstacle and provides the obstacle information by haptic feedback. Also, they are designing the database server system to share the obstacle information. Particularly the composed system can quickly give an obstacle-avoidance route using shared obstacle information. Smart walking aids systems for visually impaired people will advance more rapidly by applying machine learning and intelligent systems.

• Journal of International Academy of Physical Therapy Research
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• v.2 no.2
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• pp.329-338
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• 2011

The purpose of this study is to examine the effect of stabilization, resistance exercise, and combined exercise for lumbar on balance and walking ability of elderly. This study selected 22 subjects of over 65 years old elderly women who satisfy the study condition from A, B and C Senior Citizen's Center, in Daegu. The subjects were divided into groups; 7 for resistance exercise group, 8 for stabilization exercise group, and 7 for combined exercise group(resistance and stabilization exercise). The exercises were conducted for 60min a day, three times a week for 12 weeks. Balance and walking ability were checked before the exercise, 6 weeks later, and 12 weeks later. First, all lumbar muscle strengthening exercises were effective for static balance which changed according to exercising period. In dynamic balance, the resistance exercise group showed significant improvement in sit to stand. Stabilization exercise group showed significant improvement in all factors. The combined exercise group showed significant improvement in sit to stand and timed up and go. There was no difference between the exercise types. Second, the resistance exercise group showed significant change in Cadence which changed according to exercising period. The combined exercise group showed significant improvement in all factors. Between the exercise types, combined exercise was a bit more effective than resistance exercise. According to the result of 12 weeks of lumbar muscle exercise, combined exercise is considered to be the most effective exercise to prevent fall as it helps balance and walking ability slightly more than other exercises. Therefore, this study can understand the risk factors for fall accidents that frequently occur among elderly and adopt the combined exercise to prevent fall which in turn will prevent secondary problems occur from fall accidents and improve quality of life of elderly.