• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.2
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• pp.150-160
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• 2012

The purpose of this study is to examine the relationship between children's walking safety or risk of traffic accident and the physical environments around 20 public elementary schools in Changwon-si, Gyeongsangnam-do. Field surveys were conducted to assess the street-level objective and subjective walking environments. The GIS method was used for measuring the neighborhood-level land use patterns. Children's walking safety and risk of traffic accident data were collected from the 6,381 grade 5 to 6 students attending 18 elementary schools through the questionnaire survey. Correlation analysis showed that walking safety and risk of traffic accident of the elementary students were associated with the number of temporary or permanent obstacles on the sidewalk, traffic safety signs, driveway and street intersections, street lights, and percentage of detached housing area and road area on neighbourhood-level. This research will promote to help with constructing a safe routes to school and walking-friendly healthy community.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.139-145
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• 2006

This paper develops pedestrian fatality models capable of producing the probability of pedestrian fatality in collision between vehicles and pedestrians. Probabilistic neural network (PNN) and binary logistic regression (BLR) ave employed in modeling pedestrian fatality pedestrian age, vehicle type, and collision speed obtained from reconstructing collected accidents are used as independent variables in fatality models. One of the nice features of this study is that an iterative sampling technique is used to construct various training and test datasets for the purpose of better performance comparison Statistical comparison considering the variation of model Performances is conducted. The results show that the PNN-based fatality model outperforms the BLR-based model. The models developed in this study that allow us to predict the pedestrian fatality would be useful tools for supporting the derivation of various safety Policies and technologies to enhance Pedestrian safety.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.280-286
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• 2019

This study verified the difference in biomechanical variation and the pattern of the lower limb between using or not using functional insoles on the gait of elderly people. Ten females subjects were selected (age: 73.2 years, height: 152.1 cm, body mass: 59.4 kg) for testing their gait with using functional insoles and without using functional insoles. The gait motions were captured with the Qualisys system and the gait parameters were calculated with Visual-3D. As a result, the subjects' stride length and swing time were significantly increased (p<.05). Also, the lower limb's extension moment was significantly increased (p<.05) when using the insole. These differences suggest the functional insole used in the experiment increases the subjects' gait stability. However, to generalize the results of this study, it is necessary to accumulate more quantitative data with more subjects. Further studies to examine gait variables and changes of walking patterns need to be conducted by gathering and utilizing the results of those subjects who have used insoles for a long period of time.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.1
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• pp.65-72
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• 2016

In this study, a fully active transfemoral prothesis with a knee joint is designed considering stair walking conditions. Since the torque at the knee joint required for stair walking condition is relative high compared with the one in normal walking condition, the proposed design has high torque generating mechanism. Moreover, the transfemoral prothesis is designed in compact size to reduce its weight, which is related to comfortable fit and fatigue of patients. Flat type BLDC motor is used for simple and compact structure and various components are used to generate required torque with target working angle and speed. The weight reduction of structure is carried out using optimization method after the initial design process is complete. The optimization is conducted under the load conditions of stair walking. The optimized design is validated via finite element analysis and experiments. As a result, the weight is reduced using topology and shape optimization but maintaining the safety of structure. Also the space efficiency is improved due to its compact size.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.4
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• pp.1-10
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• 2022

Attempts to interpret human perspectives using computer vision have been developed in various fields. In this paper, we propose a method for evaluating the walking environment through semantic segmentation results of images from road images. First, the Kakao Map API was used to collect road images, and four-way images were collected from about 50,000 points in JeonJu. 20% of the collected images build datasets through crowdsourcing-based paired comparisons, and train various regression models using paired comparison data. In order to derive the walkability score of the image data, the ranking score is calculated using the Trueskill algorithm, which is a ranking algorithm, and the walkability and analysis using various regression models are performed using the constructed data. Through this study, it is shown that the walkability of Jeonju can be evaluated and scores can be derived through the correlation between pixel distribution classification information rather than human vision.

• KIISE Transactions on Computing Practices
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• v.22 no.11
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• pp.576-582
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• 2016

Currently, every person possesses a smart phone due to the development of the IT industry. However, crosswalk pedestrian accidents have been sharply increasing due to smart phone use. If a traffic light can recognize smart phones when a smart-phone user approaches and arrives at a given sign, many accidents could be reduced by using beacon signals. Before the era of smart phones, the accident rate involving cell phone use was relatively low. Nevertheless, when considering the development of IT equipment that produces a threat to human life, government cannot regulate smart phone use outside. The purpose of this paper is to indirectly warn a smart phone user in order to reduce the accident rates.

• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.159-166
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• 2009

The purpose of this study was to develop and automatic gait event detection algorithm using single accelerometer which is attached at the top of the shoe. The sinal vector magnitude and anterior-posterior(x-axis) directional component of accelerometer were used to detect heel strike(HS) and toe off(TO), respectively. To evaluate proposed algorithm, gait event timing was compared with that by force plate and kinematic data. In experiment, 7 subjects performed 10 trials level walking with 3 different walking conditions such as fast, preferred & slow walking. An accelerometer, force plate and 3D motion capture system were used during experiment. Gait event by force plate was used as reference timing. Results showed that gait event by accelerometer is similar to that by force plate. The distribution of differences were spread about $22.33{\pm}17.45m$ for HS and $26.82{\pm}14.78m$ for To and most error was existed consistently prior to 20ms. The difference between gait event by kinematic data and developed algorithm was small. Thus it can be concluded that developed algorithm can be used during outdoor walking experiment. Further study is necessary to extract gait spatial variables by removing gravity factor.

• Journal of Biomedical Engineering Research
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• v.24 no.2
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• pp.133-140
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• 2003

In this study, muscle activity was measured using surface EMG (sEMG) during a voluntary maneuver (ankle dorsiflexion) in the supine position was compared pre and post gait training. Nine patients with incomplete spinal cord injury participated in a supported treadmill ambulation training (STAT), twenty minutes a day, five days a week for three months. Two tests, a gait speed test and a voluntary maneuver test, were made the same day, or at least the same week, pre and post gait training. Ten healthy subjects' data recorded using the same voluntary maneuvers were used for the reference. sEMG measured from ten lower limb muscles was used to observe the two features of amplitude and motor control distribution pattern, named response vector. The result showed that the average gait speed of patients increased significantly (p〈0.1) from 0.47$\pm$0.35 m/s to 0.68$\pm$0.52 m/s. In sEMG analysis, six out of nine patients showed a tendency to increase the right tibialis anterior activity during right ankle dorsiflexion from 109.7$\pm$148.5 $mutextrm{V}$ to 145.9$\pm$180.7 $mutextrm{V}$ but it was not significant (p〈0.055). In addition, only two patients showed increase of correlation coefficient and total muscle activity in the left fide during left dorsiflexion. Patients' muscle activity changes after gait training varied individually and generally depended on their muscle control abilities of the pre-STAT status. Response vector being introduced for quantitative analysis showed good Possibility to anticipate. evaluate, and/or guide patients with SCI, before and after gait training.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.6
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• pp.45-52
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• 2023

Recently, as the importance of walking in daily life has been emphasized, projects to guarantee walking rights and create a pedestrian environment are being promoted throughout the region. In previous studies, a pedestrian environment assessment was conducted using Jeonju-si road images, and an image comparison pair data set was constructed. However, data sets expressed in numbers have difficulty in generalizing the judgment criteria of pedestrian environment assessors or visually identifying the pedestrian environment preferred by pedestrians. Therefore, this study proposes a method to interpret the results of the pedestrian environment assessment through data visualization by building a web application. According to the semantic segmentation result of analyzing the walking environment components that affect pedestrian environment assessors, it was confirmed that pedestrians did not prefer environments with a lot of "earth" and "grass," and preferred environments with "signboards" and "sidewalks." The proposed study is expected to identify and analyze the results randomly selected by participants in the future pedestrian environment evaluation, and believed that more improved accuracy can be obtained by pre-processing the data purification process.

• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.49-58
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• 2008

The purpose of this study was to identify effects of walking speed and a cognitive task during treadmill walking on gait variability. Experiments consisted of 5 different walking speeds(80%, 90%, 100%, 110% and 120% of preferred walking speed) with/without a cognitive task. 3D motion analysis system was used to measure subject's kinematic data. Temporal/spatial variables were selected for this study; stride time, stance time, swing time, step time, double support time, stride length, step length and step width. Two parameters were used to compare stride-to-stride variability with/without cognitive task. One is the coefficient of variance which is used to describe the amount of variability. The other is the detrended fluctuation analysis which is used to infer self-similarity from fluctuation of aspects. Results showed that cognitive task may influence stride-to-stride variability during treadmill walking. Further study is necessary to clarify this result.