• Journal of Mechanical Science and Technology
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• v.18 no.12
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• pp.2069-2079
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• 2004

This paper represents the description of a complex mathematical model of biomechanical interaction for human-rifle system during shooting. The model is developed by finite element method using bar elements. And three typical shooting positions, i.e. standing, kneeling and prone are used. Characteristics of interior/exterior ballistics and behaviors of human-rifle system are evaluated by this model, which takes into account the influence of environment, bullet, powder, barrel geometry parameters and anthropological parameters. The results of this study can be applied to anthropology, biomechanics, medical science, gait analysis, interior ballistics and exterior ballistics.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.82-83
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• 1998

In this study, variation of ground reaction force and energy consumption are investigated while walking with four different AK prostheses in order to obtain basic biomechanical data for developing AK prosthesis for Korean. It is a important information to investigate ground reaction force(GRF) and energy consumption to evaluate efficiency and stability of the prostheses.

• The Journal of Korean Physical Therapy
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• v.24 no.2
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• pp.57-65
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• 2012

Purpose: This study was to investigate the effect of biomechanical intervention, based on the custom seating system on the activities of a mouse click for children with cerebral palsy. Methods: Thirteen children with cerebral palsy participated in this study. We compared reaction time and frequency for proper mouse click in the subject's typical position, in addition to an intervention position. The intervention position conformed to the principle and practice of research on promoting the upper-extremity movement and postural control. The intervention position was achieved through an external postural support, which was based on the custom seating system. Results: Reaction time and frequency for proper mouse click were moderately improved in the intervention position, compared with that of the typical position. There was a statistically significant difference between the typical position and that of the intervention position (p<0.05). Conclusion: Results provide evidence of the positive effects of functional seating on the activities of a mouse click for children with cerebral palsy.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.107-113
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• 2007

The purpose of this study were to investigate the effects of knee brace on the knee muscular neuro-biomechanical variables during the rebound in female highschool basketball players. Twelve high school female ($17.9{\pm}0.8years$) basketball players rebound jumped for maximal vertical height to sufficiently stress the anterior cruciate ligament with and without knee brace. Kinematic data were collected to estimate the knee flexion, abduction angles and jump height. The EMG data from the biceps femoris and rectus femoris was used to estimate the ratio of quadriceps muscle activity. Female athletes with knee brace showed more reduced the knee abduction angle and the ratio of quadriceps muscle activity at foot contact phase than without knee brace. In conclusion, Female athletes with brace reduced knee anterior cruciate ligament loads.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1074-1077
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• 2002

Biomechanical behavior of the human femur is very important in various clinical situations. In this study, the data of FE models based on DICOM file exported from Computed tomography(CT). We generated FE models(voxel model, tetra model) of human femur using CT slide image. We compared them with Yon Mises stress results derived from finite element analysis(FEA). Comparing the two models, we found a correlation of them. As a result, the tetra model based proposed marching cube algorithm is a valid and accurate method to predict parameters of the complex biomechanical behavior of human femur.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.345-350
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• 2003

We were preferred bovine cortical bone to the others in xenobonegrafts for human and small animals, because those were not limited to supply and have sufficient size for bone transplantation. The strength (ST) and stiffness (SF) of cortical bone in bone grafts were very important. The strength and stiffness of cortical bone were much difference according to position of long bone in bovine limbs because which were biomechanical different to bear body weight. Therefore, we determinated by three bending point test methods the strength and stiffness of cortical bone which were collected in diaphysis of humerus, radius, femur and tibia of bovine. In the results, the strengths and stiffness among these were highest in radius by ST: 253.84$\pm$40.80 MPa, SF: 7.89$\pm$1.91 Gpa and lowest in humerus by ST: 185.69$\pm$28.54 MPa, SF: 6.21$\pm$1.22 Gpa.

• Journal of Biomedical Engineering Research
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• v.32 no.3
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• pp.191-197
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• 2011

Lifting chair is a typical assistive product to aid for standing up and sitting down for persons with disability. It is particularly useful for the elderly persons whose muscular system is weakened by degenerative joint disease. This paper describes biomechanical assessments of lifting chair with hip-up function. In experiments we measured 3D motion and electromyographic(EMG) signal on the femoral muscle when subject performs the standing motion on the predetermined seat height. Based on assessment of the standing motion, we select the hip-up angle as 15 degrees to cover the relative femoral angle when EMG peak value is appeared. Using an implemented prototype lifting chair with hip-up function we perform standing experiments with five subjects. The experimental results show that the lifting and hip-up functions are effective to assist for standing up motion with less muscle force.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.2
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• pp.197-202
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• 2001

The biomechanical analysis of the load carrying effect on different floor surfaces has been conducted. Four different floor surfaces were prepared for ten subjects with each walking at a fixed velocity(1.33 m/sec) while carrying five different loads. The results showed that because of the significant interaction effect between floor slipperiness and the load carrying task, the load carrying effect should be analyzed according to different levels of the floor slipperiness, especially contaminant floors. On oily surfaces, slip distance(SD) and heel velocity (HV) increased whereas stride length(SL) decreased as load increased. In other words, significantly longer SD, faster HV, and no normal gait were found as load increased. As a result, a different protocol should be applied to measure floor slipperiness on oily floors as compared to dry surfaces for tribological approach.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.8 s.185
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• pp.185-194
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• 2006

In this paper, three dimensional finite element analyses have been performed to investigate the biomechanics of vertebroplasty in patient accurate FE models have been constructed from CT images of a PMMA injected vertebra. In order to apply various material properties of the spine(T12), the functional relation between the well known apparent density and HU(Hounsfield unit) from CT image were employed and thus real material properties can be assigned to each element of FE model. The FE analysis showed similar results with the experiments. With this approach accurate analysis of the vertebroplasty and its clinical applications can be expected.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.240-243
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• 2005

Osteoporosis, one of the age-related disease causes vertebra body fracture due to weakening trabecular bone and makes a substantial effect on load sharing among vertebras. Recently, vertebroplasty is one of the most popular treatment, as augmenting PMMA into vertebra. Biomechanical studies about vertebroplasty have been evaluated by several experiments or analysis under static loading but there has been no study on response under dynamic loading. This study included the FE analysis of patients who treated vertebroplasty under dynamic loading. For this study, 3-D FE model of lumbar spine(L1-L2) was modeled from CT scanning data and compared with experimental results in vitro in order to validate this model. Biomechanical behavior about each of normal person, osteoporotic patient and patient treated vertebroplasty for quantitative evaluations of vertebroplasty was compared and investigated.