• Korean Journal of Applied Biomechanics
• /
• v.18 no.1
• /
• pp.63-72
• /
• 2008

The purpose of this study was to compare and analyze the effects of exercise types on lower extremity muscle activity in stroke patients. For the purpose, the subjects of this study were classified into three groups such as therapeutic exercise group(n=7), elastic band group(n=7), and stretch reflex group(n=7). The three exercise programs were 5 times a week for 8 weeks. The stretch reflex group revealed higher in iliopsoas and biceps femoris %MVIC than the therapeutic exercise group and elastic band group, whereas elastic band group revealed lower in tibialis anterior %MVIC than therapeutic exercise group in the primary single-limb support. The stretch reflex group revealed higher in iliopsoas %MVIC than the therapeutic exercise group and elastic band group, whereas stretch reflex group revealed lower in medial gastrocnemius %MVIC than therapeutic exercise group in the secondary double support phase.

• Korean Journal of Applied Biomechanics
• /
• v.30 no.3
• /
• pp.247-253
• /
• 2020

Objective: This study aimed to examine the effects of real-time visual feedback gait training on gait stability in older adults. Method: Twelve older adults participated in this study, being divided into 2 groups including a) visual feedback (VF) and b) non-visual feedback (NVF) groups. For 4 weeks, VF performed a treadmill walking training with real-time visual feedback about their postural information while NVF performed a normal treadmill walking training. For evaluations of gait stability, kinematic data of 15-minute treadmill walking were collected from depth-based motion capture system (30 Hz, exbody, Korea). Given that step lengths in both right and left sides were determined based on kinematic data, three variables including step difference, coefficient of variation, approximate entropy were calculated to evaluate gait symmetry, variability and complexity, respectively. Results: For research findings, VF exhibited significant improvements in gait stability after 4-week training in comparison to NVF, particularly in gait symmetry and complexity measures. However, greater improvement in gait variability was observed in NVF than VF. Conclusion: Given that visual feedback walking gives potential effectiveness on gait stability in older adults, gait training with visual feedback may be a robust therapeutic intervention in people with gait disturbances like instability or falls.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.24 no.3
• /
• pp.304-309
• /
• 2014

In this paper, we design a hybrid wheeled and legged mobile robot with a waist joint. The proposed hybrid mobile robot is designed to have a hybrid structure with leg and wheel for the efficient movement in flat and uneven surfaces. The proposed robot have a waist joint that is used to stably transform from wheeled driving to legged walking of the robot and to overcome non-flat surface. In order to recognize various environments we use LRF sensor, PSD sensor, CCD camera. Also, a motion planning method for hybrid mobile robot with a waist joint is proposed to select wheeled driving motion and legged walking motion of the robot based the environment types. We verify the efficient mobility of the developed hybrid mobile robot through navigation experiments using the proposed motion planning method in various environments.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.22 no.5
• /
• pp.216-223
• /
• 2023

As the technology and level of autonomous vehicles advance and they drive in more diverse road environments, an intuitive and efficient interaction system is needed to resolve and respond to the situations the vehicle faces. The development of driving technology from the perspective of autonomous driving has the ultimate goal of responding to situations involving humans or more. In particular, in complex road environments where mutual concessions must be made, the role of a system that can respond flexibly through efficient communication methods to understand each other's situation between vehicles or between pedestrians and vehicles is important. In order to resolve the status of the vehicle or the situation being faced, the provision and method of information must be intuitive and the efficient operation of an autonomous vehicle through interaction with intention is required. In this paper, we explain the vehicle structure and functions that can display information about the situation in which the autonomous vehicle driving in a living lab can drive stably and efficiently in a diverse and complex environment.

• International Journal of Highway Engineering
• /
• v.6 no.4 s.22
• /
• pp.91-100
• /
• 2004

This study was Performed to evaluate applicability of color flexible pavement concrete (CFPC) for motorway pavement. Color flexible pavement has been applied to non-motorway pavements, such as pedestrian and bicycle road. Two polymers were used to modify the binder and to strengthen the stiffness of pavement mixture. Waste paper was used to prevent the asphalt of gap-grade mixture from draining. Marshall properties, indirect tensile strength(ITS), tensile strength ratio(TSR) before and after freezing-and-thawing treatment and artificial aging, permanent deformation and fatigue life were measured. Color bituminous concrete mixtures used this study had nearly the same quality in mechanical properties when compared with conventional asphalt concrete mixtures manufactured with AP-3 and all mixtures satisfied with domestic specification for motorway pavement. Therefore, it is proved that the color bituminous concrete used this study can be applied for motorway pavement.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.14 no.2
• /
• pp.128-133
• /
• 2021

Currently, autonomous vehicle markets are commercializing a third-level autonomous vehicle, but there is a possibility that an accident may occur even during fully autonomous driving due to stability issues. In fact, autonomous vehicles have recorded 81 accidents. This is because, unlike level 3, autonomous vehicles after level 4 have to judge and respond to emergency situations by themselves. Therefore, this paper proposes a vehicle crisis detection system(VCDS) that collects and stores information outside the vehicle through CNN, and uses the stored information and vehicle sensor data to output the crisis situation of the vehicle as a number between 0 and 1. The VCDS consists of two modules. The vehicle external situation collection module collects surrounding vehicle and pedestrian data using a CNN-based neural network model. The vehicle crisis situation determination module detects a crisis situation in the vehicle by using the output of the vehicle external situation collection module and the vehicle internal sensor data. As a result of the experiment, the average operation time of VESCM was 55ms, R-CNN was 74ms, and CNN was 101ms. In particular, R-CNN shows similar computation time to VESCM when the number of pedestrians is small, but it takes more computation time than VESCM as the number of pedestrians increases. On average, VESCM had 25.68% faster computation time than R-CNN and 45.54% faster than CNN, and the accuracy of all three models did not decrease below 80% and showed high accuracy.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.7 no.2
• /
• pp.41-46
• /
• 2013

IIn this paper, active trasfemoral prosthesis leg is designed for the handicapped who lost their legs upon knee. It is important to design proper knee joint to mimic walking motion of hyman. 1 degree-of-freedom active trasfemoral prosthesis leg is designed with knee joint. Operating angle and torque have been calculated using kinematics of three linkages in prosthesis leg. Finite element analysis of major components is performed to evaluate the safety under operating condition and to reduce weights. Minimum volumes of components are obtained by optimization as satisfying safety requirements. The results show that about 35% of weight of components is reduced.

• Journal of Yeungnam Medical Science
• /
• v.13 no.2
• /
• pp.211-224
• /
• 1996

The patients of developmental dislocation of the hip(DDH) are almost found after walking age because of early diagnosis of DDH in younger children is not easy. A controversy still exists as to the relative value of closed and operative management in the treatment of a child who has reached walking age. This study is a report of the results of 16 patients(17 cases) in developmental dislocation of the hip who have visited our hospital at the age of 9 months to 3 years old, and have been followed more than 12 months (12-112 months) on review of plain radiographs and arthrograms. The results were as follows : 1. The age at diagnosis was 16.4 months(9-31 months) in average. The methods of treatment were conservative for 8 cases, and operation for 4 cases and secondary operation for 5 cases who were failed with conservative therapy. 2. By Severin's radiologic grade, the result was good in 4 cases, fair in 3 cases and poor in 1 case in conservative treatment. In operative treatment, fair was in 2 cases and poor in 2 cases. In secondary operative patients who were failed with conservative therapy, good was in 2 cases, fair in 2 cases and poor in 1 case. 3. Avascular necrosis of femoral head was developed in 3 cases. 4. In the good reduction as determined by arthrogram according to Race and Herring, we can get a favorable result in conservative treatment, and in the poor reduction as determined by arthrogram, the better result in operative treatment can be expected.

• Proceedings of the KIEE Conference
• /
• 2006.07d
• /
• pp.1977-1978
• /
• 2006

This paper discusses the method of vision based sensor fusion system for biped robot walking. Most researches on biped walking robot have mostly focused on walking algorithm itself. However, developing vision systems for biped walking robot is an important and urgent issue since biped walking robots are ultimately developed not only for researches but to be utilized in real life. In the research, systems for environment recognition and tele-operation have been developed for task assignment and execution of biped robot as well as for human robot interaction (HRI) system. For carrying out certain tasks, an object tracking system using modified optical flow algorithm and obstacle recognition system using enhanced template matching and hierarchical support vector machine algorithm by wireless vision camera are implemented with sensor fusion system using other sensors installed in a biped walking robot. Also systems for robot manipulating and communication with user have been developed for robot.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.5
• /
• pp.399-405
• /
• 2007

This paper deals with the controller for a stable walking of a humanoid robot using genetic algorithm. A humanoid robot has instability during walking because it isn't fixed on the ground, and its nonlinearities of the joints increase its instability. If controller isn't robust, the robot may fall down at the ground during walking because of its nonlinearities. To solve this problem, robust controller is required to reduce the effect of nonlinearities and to gain the good tracking performance. In this paper, motion controller that is based on fuzzy-sliding mode controller is proposed. This controller can remove the effect of the saturation by limitation of the input voltage. It also includes compensator for reducing the effect of the nonlinearity by backlash and PI controller improving the tracking performance. In here, genetic algorithm is used for searching the optimal gains of the controller. From the given controller, a humanoid robot can moved more preciously. All the processes are investigated through simulations and are verified experimentally in a real joint system for a humanoid robot.