• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.4 no.1
• /
• pp.101-110
• /
• 2004

The robots that will be needed in the near future are human-friendly robots that are able to coexist with humans and support humans effectively. To realize this, humans and robots need to be in close proximity to each other as much as possible. Moreover, it is necessary for their interactions to occur naturally. It is desirable for a robot to carry out human following, as one of the human-affinitive movements. The human-following robot requires several techniques: the recognition of the moving objects, the feature extraction and visual tracking, and the trajectory generation for following a human stably. In this research, a predictable intelligent space is used in order to achieve these goals. An intelligent space is a 3-D environment in which many sensors and intelligent devices are distributed. Mobile robots exist in this space as physical agents providing humans with services. A mobile robot is controlled to follow a walking human using distributed intelligent sensors as stably and precisely as possible. The moving objects is assumed to be a point-object and projected onto an image plane to form a geometrical constraint equation that provides position data of the object based on the kinematics of the intelligent space. Uncertainties in the position estimation caused by the point-object assumption are compensated using the Kalman filter. To generate the shortest time trajectory to follow the walking human, the linear and angular velocities are estimated and utilized. The computer simulation and experimental results of estimating and following of the walking human with the mobile robot are presented.

• Journal of International Academy of Physical Therapy Research
• /
• v.4 no.2
• /
• pp.562-565
• /
• 2013

The fact that flip-flops, one of many different types of unstable shoes, are light and relatively easy to put on, accounts for their popularity among people. But because flip-flops rely heavily on the support of a single thong between your first and second toes, they impose a huge amount of pressure onto lower leg. Thus in the following experiment we tried to examine the different effects of flip-flops and running shoes in terms of their effect on muscle activity and fatigue of tibialis anterior and gastrocnemius during walking. In order to measure an electromyogram we used Free EMG system. 10 men and 10 women in running shoes ran on treadmills for 15 minutes at 4.8km/h, 2 days later the same experiment was carried out, but this time, in flip-flops. p value turned out to be greater than .05 and thus there was no considerable difference between the effects of flip-flops and running shoes on muscle activity and fatigue during walking. Therefore we conclude that despite the fact that flip-flops are considered unstable, their effects on muscle activity and fatigue of tibialis anterior and gastrocnemius are negligible.

• Journal of the Korean Society of Physical Medicine
• /
• v.11 no.4
• /
• pp.71-78
• /
• 2016

PURPOSE: The purpose of this study was to investigate which treadmill walking training mode is more effective strategy for improving pulmonary function of persons with chronic stroke. METHODS: Twenty-one chronic stroke patients were allocated and randomly to an experimental group (treadmill training with randomized speed control, n=11) and a control group (treadmill training without speed change, n=10). All participants received 30 minutes of neurodevelopmental treatment. In addition, the two groups performed treadmill training for 20 minutes each time with or without speed change. Speed change was applied 40%, 50%, 60%, 70% of Heart Rate Reserve. All the exercise programs lasted six weeks, with five times per week. Pulmonary function was assessed before and after exercise program by using forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and maximal voluntary ventilation (MVV). RESULTS: In the both groups, FEV1 was significantly increased after training (p<.05). Compared to the control group, the experimental group showed 11.9% larger amount of change (p<.05). In the experimental group, FVC and MVV were significantly increased after training (9.9%, 7.6%, respectively) (p<.05). But in the control group, there was no significant difference in the FVC and MVV after training. CONCLUSION: Treadmill training with randomized speed control will be a better positive rehabilitation program than treadmill training without speed change to improve pulmonary function in persons with chronic stroke.

• Journal of the Korean housing association
• /
• v.20 no.4
• /
• pp.79-88
• /
• 2009

A planned access method on constantly-changing-community unit plan changes and develops based on the periodical situation and also plan theory. In this research, it is to present the link between the theory of complex city change and the plan factor of it, and to show how Korean residential complex plan has changed as time passed and how new concept of city plan came up and by applying new methods how can this affect our real world and the past plan. In the phase of analysis, it analyzed the flow of 'community unit plan' and its theory and investigated the factor of compositional space and built a analysis frame. The factors of community unit plan are space structure, size and shape of block, population, distribution of facilities and movement system. It chose the place that can represent the flow of community unit plan trand and that indicates the obvious development leading to Jamsil (1975), Gwa Chun (1980), Mok Dong (1983), Sang Ge (1985), Ilsan (1989), Dong tan (2001) and Eun Jung (2003) total of 7 places. And to compare a similar size of the city, it selected a small community unit. Based on the result of theoretical study and prior research, it can be said that the space composition style has change from a whole complete complex area to a linked-cross over community unit and the access of urban level was on set. Also, a pedestrian walking area was secured and the dense of building structure and pleasant environment wanting need was in balance. For facility plans, the usage of facility and functional change brought change of type, size and disposition. The walking area for pedestrian became a huge matter. Therefore, market, education, public facilities and green system collaborated to co-build a whole community unit and activated the walking environment. Also, public transportation, environment friendly city organization was built.

• Annals of Clinical Neurophysiology
• /
• v.4 no.1
• /
• pp.44-50
• /
• 2002

Introduction : Orthostatic tremor develops in the legs while standing up with no weakness, pain or imbalance in the leg and the tremor is characteristically not observed when walking. However there have been some confusions about orthostatic tremor in several aspects. For the past ten years, we have observed 4 patients with orthostatic tremor. In each case tests were performed to investigate the following three important areas of inquiry about orthostatic tremor. Firstly, whether this disorder is an independent diagnostic entity or a variant of essential tremor. Secondly, whether the progress of this disorder is specifically related with standing posture. Lastly, the nature of the pathophysiologic mechanism behind the appearance of the tremor when standing after the lapse of a certain latent period and its disappearance upon the commencement of walking. Methods : Our 4 cases of orthostatic tremor were studied clinically, electrophysiologically, and pharmacologically. Electrophysiological tests included tremor spectrum test and electromyography. Results : We observed the presence of this tremor in several other tonic postures, as well as its absence, in a vertically lifted position from all our cases. Our cases registered a variable tremor frequency between 5 and 12 Hz according to the tremor spectrum test and EMG. Furthermore all our 4 cases demonstrated patterns of both synchronous EMG activity and alternating EMG activity at various times in homologous muscles of both legs. Orthostatic tremor was improved significantly with propranolol as well as clonazepam. Conclusions : From the results of our study we drew the following conclusions. It is probable that orthostatic tremor is simply a variant of essential tremor rather than being an independent diagnostic entity and that in most cases its development is specifically related with muscle contraction rather than merely with the act of standing. Furthermore we discovered a clue in the previously described neural control mechanism that the nuclear bag fibers in the muscle spindle have lag time of several seconds in their response to muscle strength and that their baseline does not reset fully in rapidly moving muscle. This neural control mechanism could offer sufficient explanation for the phenomena of tremor appearance when standing and disappearance when walking in orthostatic tremor.

• Journal of the Korean Society of Physical Medicine
• /
• v.12 no.2
• /
• pp.129-136
• /
• 2017

PURPOSE: The purpose of this study was to compare the gait of elderly patients with and without dementia to investigate the possibility of an ambulation assessment test as a diagnostic tool for dementia. METHODS: A total of 96 subjects were included with 60 participants without dementia (control group) and 36 patients with dementia (dementia group). To compare the walking ability of the two groups, a 4-m walking test (4MWT) and Groningen Meander Walking Test (GMWT) were conducted. The GMWT is graded by amount of time in seconds and by number of oversteps outside the track. Mann-Whitney U test was used to compare the gait between the groups and the area under the curve (AUC) with Received Operating Characteristic (ROC) curve was analyzed. Statistical significance was considered at a p<.05, with a 95% confidence interval. RESULTS: There were statistically significant differences (p<.05) between the dementia group and the control group for the 4MWT, GMWTSEC, and GMWTSTEP scores. The AUC was .95 for 4MWT, .92 for GMWTSEC, and .96 for GMWTSTEP with the 95% confidence interval. The cut-off values of the ROC curve were 1.03m/s for 4MWT, 10.8 second for GMWTSEC, and 3.75 steps for GMSTEP. CONCLUSION: In our study, we investigated the utility of ambulatory assessment tools to predict dementia. The results of this study suggest that the 4MWT and the GMWT used in this study are appropriate assessment tools for dementia prediction.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.1308-1317
• /
• 2009

The mass transit networks in Korea, such as buses, metro and subway, are co-related and the number of transfer points, in which a lot of pedestrian movement is generated, are rising. The functions of the transfer centers, in which several travel modes cross at a point, have to include convenience and comfort for pedestrians using the transfer centers, and such functions can make transit a more attractive travel option and thus eventually contribute to increases in ridership. However, the guidelines for station layouts and their assessments in transfer stations are not suggested so far. So the pedestrian pattern data (pedestrian walking distances and times, pedestrian approaching distances and times, pedestrian walking paths in the inside of stations) was collected and analyzed. Based on the results of the analysis, the ways to measure the quality of comfort for those who using transfer facilities were suggested using the times that pedestrians consume to transfer from a travel mode to another. The walking time of pedestrians at the inside of stations was also measured by pre-selected pedestrian pathways as the guidelines for station layout assessment in transfer facilities.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.2
• /
• pp.145-151
• /
• 2006

A large interindividual variability and some abnormally kinematic patterns at the lower extremity were the main features of the gait in children with Down syndrome. The purposes of this study were to investigate the gait asymmetry and biomechanical difference between dominant leg and non dominant leg in children with Down syndrome. Seven boys with Down Syndrome(age: $120{\pm}0.9yrs$, weight $34.4{\pm}8.4kg$, leg length: $68.7{\pm}5.0cm$) participated in this study. A 10.0 m ${\times}$ 1.3 m walkway with a firm dark surface was built and used for data collection. Three-dimensional motion analyses were performed to obtain the joint angles and range of motions. The vertical ground reaction forces(%BW) and impulses($%BW{\cdot}s$) were measured by two force plates embedded in the walkway. Asymmetry indices between the legs were computed for all variables. After decision the dominant leg and the non dominant leg with max hip abduction angle, paired samples t-test was employed for selected kinematic and ground reaction force variables to analyze the differences between the dominant leg and the non dominant leg. The max hip abduction angle during the swing phase showed most asymmetry, while the knee flexion angle at initial contact showed most symmetry in walking and running. The dominant leg showed more excessive abduction of hip in the swing phase and more flat-footed contact than the non dominant leg. Vertical peak force in running showed more larger than those of in walking, however, vertical impulse showed more small than walking due to decrease of support time. In conclusion, the foot of dominant leg contact more carefully than those of non dominant leg. And also, there are no significant difference between the dominant leg and the non dominant leg in kinematic variables and ground reaction force due to large interindividual variability.

• Journal of Convergence for Information Technology
• /
• v.10 no.2
• /
• pp.21-31
• /
• 2020

This study tested the effectiveness of commercialized smartphone apps in improving walking activities among college students. 66 participants were randomized into each of four groups that was used different behavior change strategies: monetary rewards app, goal setting and feedback app, gaming app, and self-monitoring control group. 45 participants who completed the experimentation was included in data analysis. Repeated measures ANOVA resulted in statistically significant time by groups interactions in recorded step counts, self-reported completed plans and self-reported walking activities scores. The Goal-setting and feedback group and the gaming group resulted in increase in both step counts and completed plans. The results were discussed in the framework of behaviorism.

• Journal of the Korean Institute of Gas
• /
• v.23 no.4
• /
• pp.74-79
• /
• 2019

Specially designed test material was used for workpiece temperature measurement in the commercial reheating furnace and a linearized thermal model was applied for real time temperature prediction. The applied furnace is a walking beam type and specification of the workpiece is a STS302 which is 160mm in width, 160mm in height and 8100mm in length. Also six thermocouples were installed in width, height and length direction for temperature measurement. Ambient temperature in the furnace was raised to 1265 Celsius degrees and it took about 2.5 hours from loading to discharging of the workpiece. As a result of the experiment, temperature of the workpiece at discharge was 1257 Celsius degrees on the average in the range of 1256 to 1259 Celsius degrees, and predicted average temperature through the thermal model was 1251 Celsius degrees. Therefore, the deviation of the analysis and test results is about 6 degrees, which is within the range of 10 degrees required by the industry.