• The Journal of Korean Physical Therapy
• /
• v.34 no.4
• /
• pp.161-167
• /
• 2022

Purpose: The purpose of this study was to investigate the effects of regular training on the uneven surface that stroke patients encounter in their daily life on their ankle joint muscle activity and balance ability. They were divided into two groups: the gait training group on uneven surfaces and the gait training group on normal surfaces. Methods: In this study, 30 patients diagnosed with stroke and undergoing rehabilitation were selected. 15 people in the uneven surface gait training group and 15 people in the flat gait training group were selected. The muscle activation of the ankle muscles was measured when walking again on a even surface after walking on an uneven surface and on a flat ground. After each gait training, the limit of stability and Romberg test were performed to evaluate the balance ability. Results: As a result of the experimental results before and after walking by group, the tibialis anterior muscle activity of the paralyzed side was significantly decreased in the uneven surface walking group. As a result of measuring balance ability after training, the limit of stability in all directions was significantly increased in the uneven surface gait training group, and the area and length moved significantly decreased in the uneven surface gait training group in the Romberg test as well (p<0.05). Conclusion: After walking on uneven surface, it was confirmed that the muscle activity of the ankle joint decreased in normal flat walking, and thus the efficiency of muscle activity was increased. In addition, it was possible to confirm the improvement of the balance ability of the gait training on the uneven surface, and in conclusion, it could be confirmed that it had an effect on the improvement of the walking ability.

• Journal of Broadcast Engineering
• /
• v.27 no.2
• /
• pp.174-184
• /
• 2022

3D human pose estimation models can be classified into a multi-view model and a single-view model. In general, the multi-view model shows superior pose estimation performance compared to the single-view model. In the case of the single-view model, the improvement of the 3D pose estimation performance requires a large amount of training data. However, it is not easy to obtain annotations for training 3D pose estimation models. To address this problem, we propose a method to generate pseudo ground-truths of multi-view human pose data from a multi-view model and exploit the resultant pseudo ground-truths to train a single-view model. In addition, we propose a multi-view consistency loss function that considers the consistency of poses estimated from multi-view images, showing that the proposed loss helps the effective training of single-view models. Experiments using Human3.6M and MPI-INF-3DHP datasets show that the proposed method is effective for training single-view 3D human pose estimation models.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.14 no.1
• /
• pp.37-53
• /
• 2012

There is considerable uncertainty in ground properties used in tunnel designs. In this study, a back analysis was performed to find optimal ground properties based on the artificial neural network facility of MATLAB program of using tunnel monitoring data. Total 81 data were constructed by changing elastic modulus and coefficient of lateral pressure which have great influence on tunnel convergence. A sensitivity analysis was conducted to establish an optimal training model by varying the number of hidden layers, the number of nodes, learning rate, and momentum. Meanwhile, the optimal training model was selected by comparing MSE (Mean Squared Error) and coefficient of determination ($R^2$) and was used to find the correct elastic moduli of layers and the coefficient of lateral pressure. In future, it is expected that the suggested method of this study can be applied to determine the optimum tunnel support pattern under given ground conditions.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.41 no.1
• /
• pp.39-49
• /
• 2018

In the satellite operation phase, a ground station should continuously monitor the status of the satellite and sends out a tasking order, and a satellite should transmit data acquired in the space to the Earth. Therefore, the communication between the satellites and the ground stations is essential. However, a satellite and a ground station located in a specific region on Earth can be connected for a limited time because the satellite is continuously orbiting the Earth, and the communication between satellites and ground stations is only possible on a one-to-one basis. That is, one satellite can not communicate with plural ground stations, and one ground station can communicate with plural satellites concurrently. For such reasons, the efficiency of the communication schedule directly affects the utilization of the satellites. Thus, in this research, considering aforementioned unique situations of spacial communication, the mixed integer programming (MIP) model for the optimal communication planning between multiple satellites and multiple ground stations (MS-MG) is proposed. Furthermore, some numerical experiments are performed to verify and validate the mathematical model. The practical example for them is constructed based on the information of existing satellites and ground stations. The communicable time slots between them were obtained by STK (System Tool Kit), which is a well known professional software for space flight simulation. In the MIP model for the MS-MG problems, the objective function is also considered the minimization of communication cost, and ILOG CPLEX software searches the optimal schedule. Furthermore, it is confirmed that this study can be applied to the location selection of the ground stations.

• Structural Engineering and Mechanics
• /
• v.90 no.2
• /
• pp.189-208
• /
• 2024

Artificial intelligence is one of the efficient methods that can be developed to simulate nonlinear behavior and predict the response of building structures. In this regard, an adaptive method based on optimization algorithms is used to train the TSK model of the fuzzy inference system to estimate the seismic behavior of building structures based on analytical data. The optimization algorithm is implemented to determine the parameters of the TSK model based on the minimization of prediction error for the training data set. The adaptive training is designed on the feedback of the results of previous time steps, in which three training cases of 2, 5, and 10 previous time steps were used. The training data is collected from the results of nonlinear time history analysis under 100 ground motion records with different seismic properties. Also, 10 records were used to test the inference system. The performance of the proposed inference system is evaluated on two 3 and 20-story models of nonlinear steel moment frame. The results show that the inference system of the TSK model by combining the optimization method is an efficient computational method for predicting the response of nonlinear structures. Meanwhile, the multi-vers optimization (MVO) algorithm is more accurate in determining the optimal parameters of the TSK model. Also, the accuracy of the results increases significantly with increasing the number of previous steps.

• Korean Journal of Applied Biomechanics
• /
• v.20 no.2
• /
• pp.167-174
• /
• 2010

This study aims to quantitatively compare and analyze kinetic variables in the motion of male and female professional golfers to suggest basic scientific materials for golf iron swing. Five male and five female professional golfers participated in this experiment. Ground reaction force and foot pressure were measured during performing 10 swings for each participants using an iron club. The result of the ground reaction force indicates that the force occurs at the left foot toward right(-) direction in the mid-downswing(E3) and impact(E4) events in X-axis, while it occurs at the right foot toward anterior(-) direction in Y-axis for both male and female, showing a big difference between them. Also, in Z-axis, large force occurs at the left foot in most events. The analyzed result on foot pressure indicates that men have the highest pressure and area at the left foot, and women have the highest ones at the right foot in the mid-downswing(E3) and impact(E4) events in the max foot pressure, ground contact area and average pressure. It is considered that there is difference of central movement methods between men and women. Thus, different education and training on golf swing should be necessary by gender due to their different patterns of golf iron swing.

• Physical Therapy Rehabilitation Science
• /
• v.7 no.2
• /
• pp.83-87
• /
• 2018

Objective: The purpose of this study was to investigate the relationship between heart rate (HR), self-awareness of exercise intensity (rating of perceived exertion, RPE), and 5-meter walk test (5MWT) of persons affected by stroke during backward walking according to the preferred stride frequency (PSF), PSF+3 and PSF+6 conditions. Design: Cross-sectional study. Methods: A total of 11 persons with stroke (9 males, 2 females) participated voluntarily. All patients underwent backward walking under the PSF, PSF+3, and PSF+6 conditions in underwater and ground environments, and each condition was performed for 5 minutes. The HR, RPE, and walking speeds were measured during walking, and the measured values from underwater and ground environments were compared. Results: The HR and RPE in the ground environment were significantly increased (p<0.05), and although the 5MWT showed an increase in speed, it was not significant. The HR and RPE in the underwater environment were also significantly increased (p<0.05), however, although the 5MWT results was increased, it was not significant. The HR and RPE were significantly increased in the PSF+6 condition (p<0.05). Conclusions: The results of this study showed that backward gait training underwater can provide an appropriate exercise intensity for stroke survivors and suggests that exercises performed in an underwater environment is more effective compared to the ground environment.

• Physical Therapy Rehabilitation Science
• /
• v.6 no.4
• /
• pp.189-195
• /
• 2017

Objective: The purpose of this study was to examine the effects of real-time visual feedback weight shift training during golf swinging on golf performance. Design: Repeated-measures crossover design. Methods: Twenty-sixth amateur golfers were enrolled and randomly divided into two groups: The golf swing training with real-time feedback on weight shift (experimental group) swing training on the Wii balance board (WBB) by viewing the center of pressure (COP) trajectory on the WBB. All participants were assigned to the experimental group and the control group. The general golf swing training group (control group) performed on the ground. The golf performance was measured using a high-speed 3-dimensional camera sensor which analyses the shot distance, ball velocity, vertical launch angle, horizontal launch angle, back spin velocity and side spin velocity. The COP trajectory was assessed during 10 practice sessions and the mean was used. The golf performance measurement was repeated three times and its mean value was used. The assessment and training were performed at 24-hour intervals. Results: After training sessions, the change in shot distance, ball velocity, and horizontal launch angle pre- and post-training were significantly different when using the driver and iron clubs in the experimental group (p<0.05). The interaction time${\times}$group and time${\times}$club were not significant for all variables. Conclusions: In this study, real-time feedback training using real-time feedback on weight shifting improves golf shot distance and accuracy, which will be effective in increasing golf performance. In addition, it can be used as an index for golf player ability.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.5
• /
• pp.1356-1363
• /
• 2007

The purpose of the study was to identify the general status of Kigong organizations introduced on Internet. We have used www.naver.com, the biggest portal site in Korea and www.nice114.co.kr, which has the longest list of the telephone numbers to look up the organizations with the index of "Kigong and Danhak" and "Mediation". Among them we screened the organizations to have the list of organizations which have been established for more than 5 years, with more than 100 trainees and whether they published books or booklets regarding Kigong by the means of telephone conversation or home page access. The number of organizations identified by telephone and Internet with the indexes of Kigongdanhak and mediation was 852. The number of organizations that passed the primary criterion was 22, and that passed the secondary criterion was 8. Among the primarily screened organization, there are 5 focusing on mediation, 5 focusing on breathing, 3 focusing on Haenggong, 4 focusing on mediation and Haenggong, 4 focusing on breathing and Haenggong and 1 focusing on mediation and breathing. In secondarily screened organizations, they called their training method as Seondo, Shinseondo or Seonhak and origin of the training method as Dangun and Hwangwung. As Sambeop training of Jigam, Josik and Geumchok provide training methods which are a little different each other, the utilization rate was low although there are some organizations that have special training using Three Bibles. It was identified that there were many texts and writings that they took as training methods other than Three Bibles. Kigong training organizations based on Korean traditional ideologies are grounded on the Three Textbooks such as , , and and the concept of Hongikingan. This ideological ground is the study of Completion of Human Beings through physical and mental training and goes with Seondo, Pungryudo and Hyunmyojido.

• The Journal of Korean Physical Therapy
• /
• v.26 no.5
• /
• pp.365-371
• /
• 2014

Purpose: The aim of this study is to examine the effects of training in vestibular sensory stimulation on balance and gait of stroke patients. Methods: Twenty patients were randomly assigned to either the experimental group (n=10) or the control group (n=10). Patients in the experimental group received rotational stimulation training, vertical-horizontal stimulation training, gait training on a flat surface with vestibular sensory stimulation, and gait training on soft ground with vestibular sensory stimulation. Patients in the control group received general treadmill gait training. The intervention was applied four times per week, 25 minutes each time, for a period of four weeks. We measured Berg Balance Scale (BBS), Biodex Balance System, Timed up to Go (TUG) test and Dynamic Gait Index (DGI) to evaluate balance and gait ability. Results: BBS differed significantly in both groups between before and after the intervention (p<0.05) and changes in BBS after the intervention differed between the two groups (p<0.05). According to the Biodex Balance System test result, only the experimental group showed significant changes in balance in the conditions of static eyes open (SEC), dynamic eyes open (DEO), and dynamic eyes closed (DEC) (p<0.05). TUG test results differed significantly between prior to and after the training in both the experimental group and the control group (p<0.05) and changes in TUG after the intervention differed significantly between the two groups (p<0.05). DGI results showed significant change after the intervention in the experimental group only (P<0.05). Conclusion: Training in vestibular sensory stimulation was effective in improving static-dynamic balance and gait ability of stroke patients.