• Computational Structural Engineering
• /
• v.10 no.4
• /
• pp.205-216
• /
• 1997

In order to trace the lateral post-buckling behaviors of thin-wafled space frames, a geometrically nonlinear finite element formulation is presented by applying incremental equilibrium equations based on the updated Lagrangian formulation and introducing Vlasov's assumption. The improved displacement field for symmetric thin-walled cross sections is introduced based on inclusion of second order terms of finite rotations, and the potential energy corresponding to the semitangential rotations and moments is consistently derived. For finite element analysis, tangent stiffness matrices of the thinwalled space frame element with 7 degrees of freedom including the restrained warping for each node are derived by using the Hermition polynomials as shape functions. A co-rotational formulation in order to evaluate the unbalanced loads is presented by separating the rigid body rotations and pure deformations from incremental displacements and evaluating the updated direction cosines of the frame element due to rigid body rotations and incremental member forces from pure deformations. Finite element solutions for the spatial buckling and post-buckling analysis of thin-walled space frames are presented and compared with available solutions and other researcher's results.

• Computational Structural Engineering
• /
• v.7 no.4
• /
• pp.103-111
• /
• 1994

Based on a variational principle of the consistent shear deformable discrete laminate theory derived in the companion paper Part I, a finite element procedure for the vibration analysis of laminated composite plates is presented. The present formulation takes the in-plane displacements of an arbitrary layer, the rotations of the cross section of each layer and transverse displacement of the plate as the state variables at a nodal point of finite element, resulting in total nodal degree of freedom of 2(n+l) +1 for the n-layered laminate. Thus, it allows to specify displacement boundary conditions of layer stretching and/or rotation of layer cross sections around the plate edge and/or lateral displacement. The developed procedure is applied to the free vibration problem for sandwich-type hybrid laminates composed of layers with drastically different material properties whose elasticity solutions are known. Comparison of analysis results with other FEM solutions showed that the present formulation yields better accuracy.

• Geotechnical Engineering
• /
• v.9 no.4
• /
• pp.65-82
• /
• 1993

A series of torsion shear tests were performed to study the drained stress -strain behavior of medium dense Santa Monica Beach sand under various stress paths. The torque was applied to both clockwise and counterclockwise directions at the end of hollow cylinder specimen. Two clip gages had been previously used to measure the changes in wall thickness and diameter of the specimen. In this study, however, the lateral strain was determined by measuring volume changes in specimen. Specimens were prepared by the air pluviation method and gaseous carbon deozide( CO2) was used to measure precisely volumetric strain in specimen. The drained stress -strain behavior of cohesionless Boils during rotation of principal stress directions was analysed based on the results of torsion shear tests. The coupling of mal stress were applied. It was also found from the test results that the atrial strain at failure decreased with increasing value.

• Computers and Concrete
• /
• v.20 no.4
• /
• pp.369-380
• /
• 2017

The effects of the vertical component of a ground motion on the earthquake performances of semi-ductile high-rise R/C structures were investigated in the present study. Linear and non-linear time-history analyses were conducted on an existing in-service R/C building for the loading scenarios including and excluding the vertical component of the ground motion. The ratio of the vertical peak acceleration to the horizontal peak acceleration (V/H) of the ground motion was adopted as the main parameter of the study. Three different near-source earthquake records with varying V/H ratio were used in the analyses. The linear time-history analyses indicated that the incorporation of the vertical component of a ground motion into analyses greatly influences the vertical deflections of a structure and the overturning moments at its base. The lateral deflections, the angles of rotation and the base shear forces were influenced to a lesser extent. Considering the key indicators of vertical deflection and overturning moments determined from the linear time-history analysis, the non-linear analyses revealed that the changes in the forces and deformations of the structure with the inclusion of the vertical ground motion are resisted by the shear-walls. The performances and damage states of the beams were not affected by the vertical ground motion. The vertical ground motion component of earthquakes is markedly concluded to be considered for design and damage estimation of the vertical load-bearing elements of the shear-walls and columns.

• The Journal of Korean Physical Therapy
• /
• v.26 no.6
• /
• pp.379-385
• /
• 2014

Purpose: This study was to determine the immediate effects of pulsed magnetic field (PMF) in subjects with upper trapezius (UT) trigger point (TrP). Methods: Fifteen subjects with UT TrP were recruited for the study's PMF group (pain threshold=$2.29kg/cm^2$), and 15 age-, weight-, and gender-matched subjects with UT TrP were recruited for control group (pain threshold=$2.25kg/cm^2$). Pressure algometer was used to measure pressure pain threshold on UT TrP and, cervical range of motion (ROM) inclinometer was used to measure cervical ROM. Surface electromyography was used to record UT, lower trapezius, and serratus anterior muscle activity and relative ratio during scapular plane abduction between pre- and post-treatment. Results: The PMF effectively improved pain threshold and concurrently increased ROM (rotation to the painful side, lateral flexion to the nonpainful side). In addition, the PMF may effectively deactivate UT activity during abduction and the muscle activity ratio between UT and serratus anterior. Conclusion: These findings provided empirical evidence that PMF can be an effective treatment method to reduce pain threshold, to increase cervical ROM, and deactivate UT activity in individuals with TrP.

• Journal of the Korean Society of Radiology
• /
• v.7 no.4
• /
• pp.271-275
• /
• 2013

Shoulder bone scan everyday life, sports activities at the side of the shoulder joint, or applying strong force in the lateral occurs. Mainly on upper arm abduction, temple, other rotational dislocation of the shoulder joint gahaejyeo as useful for observing the presence or absence of lesions is used. Shoulder PA oblique projection prevent distortion of the image due to the angle and the most useful diagnostic radiological investigate shooting angle. Shoulder blade body and the acromion and coracoid process Y-view is formed characters. $10^{\circ}$ angle between the shoulder blades and the acromion is the obstruction. $20^{\circ}{\sim}25^{\circ}$ to the Y-view of the humerus head looks superimposed, the position of the shoulder joint and seemed appropriate. $35^{\circ}$ of the humerus head superimposed on the Y-view, but above the humerus head and shoulder joints were distorted. When $45^{\circ}$ elevation observed on the side of the best has come Y-view also acromion and coracoid process is finished.

• The Journal of Internal Korean Medicine
• /
• v.42 no.5
• /
• pp.1027-1034
• /
• 2021

Objectives: This study aimed to determine the effects of Korean medical treatment on a patient with compression fractures. Methods: The patient was treated with herbal medicine and acupuncture for 51 days. Symptom changes were measured using the Numerical Rating Scale (NRS), Range of Motion (ROM), Oswestry Disability Index (ODI), and European Quality of Life Five Dimensions (EQ-5D) Scale. Results: The NRS score for lower back pain decreased from 7 to 3, and the ODI score decreased from 51.11 to 22.22. Range of motion (ROM) increased meaningfully in flexion(from 30 to 60), Left/Right lateral bending(from 10/30 to 30/45), Left/Right rotation (from 10/30 to 30/45), and the EQ-5D score also increased from 0.506 to 0.677. Conclusion: The results indicate that Korean medical treatment may be effective for managing patients' acute compression fractures.

• Physical Therapy Rehabilitation Science
• /
• v.8 no.2
• /
• pp.74-78
• /
• 2019

Objective: Myofascial release (MFR) is used to restore tissue extensibility of the fascia tissue and is considered to be useful in a number of clinical settings, such as low back pain (LBP). Dynamic myofascial release (DMFR) is the manual therapy, which combined the conventional MFR with the joint mobilization. The purpose of this study was to investigate the effects of the DMFR on trunk mobility, and furthermore, whether the increase of trunk mobility can carry over the improvement of dynamic standing balance in persons with chronic nonspecific LBP. Design: Randomized controlled trial. Methods: Thirty persons with chronic non-specific LBP participated in the study and were randomly assigned to the DMFR group (n=15) or the control group (n=15). DMFR was performed for two sessions (15 minutes/session) per week for four weeks for the treatment group. Both the DMFR and control groups were allowed to perform low-intensity physical activities during the treatment period. The Modified-modified $Sch{\ddot{o}}ber$ test (MMST) for trunk mobility and the Functional Reach Test (FRT) for dynamic standing balance were measured before and after the treatment period in both the DMFR group and the control group. Results: The MMST value of DMFR group increased significantly in all trunk range of motion (flexion, extension, lateral flexion, and rotation) after treatment, compared with the control group (p<0.05). Additionally, the FRT value of the DMFR group improved significantly after treatment, compared with the control group (p<0.05). Conclusions: We suggest that DMFR have a positive effect on trunk mobility and standing balance in persons with chronic LBP.

• The korean journal of orthodontics
• /
• v.51 no.1
• /
• pp.43-54
• /
• 2021

Objective: To investigate the cephalometric predictors of the future need for orthognathic surgery in Korean patients with unilateral cleft lip and palate (UCLP) despite long-term use of facemask with miniplate (FMMP). Methods: The sample consisted of 53 UCLP patients treated by a single orthodontist using an identical protocol. Lateral cephalograms were taken before commencement of FMMP therapy (T0; mean age, 10.45 years), after FMMP therapy (T1; mean age, 14.72 years), and at follow-up (T2; mean age, 18.68 years). Twenty-eight cephalometric variables were measured. At T2 stage, the subjects were divided into FMMP-Nonsurgery (n = 33, 62.3%) and FMMP-Surgery (n = 20, 37.7%) groups according to cephalometric criteria (point A-nasion-point B [ANB] < -3°; Wits-appraisal < -5 mm; and Harvold unit difference [HUD] > 34 mm for FMMP-Surgery group). Statistical analyses including discrimination analysis were performed. Results: In FMMP-Surgery group, the forward position of the mandible at T0 stage was maintained throughout the whole stages and Class III relationship worsened with significant growth of the mandibular body and ramus and counterclockwise rotation of the maxilla and mandible at the T1 and T2 stages. Six cephalometric variables at T0 stage including ANB, anteroposterior dysplasia indicator, Wits-appraisal, mandibular body length, HUD, and overjet were selected as effective predictors of the future need for surgical intervention to correct sagittal skeletal discrepancies. Conclusions: Despite long-term use of FMMP therapy, 37.7% of UCLP patients became candidates for orthognathic surgery. Therefore, differential diagnosis is necessary to predict the future need for orthognathic surgery at early age.

• Physical Therapy Korea
• /
• v.28 no.1
• /
• pp.47-52
• /
• 2021

Background: Compared with normal people, stroke patients have decreased voluntary craniocervical motion, which affects their balance. Objects: This study was conducted in order to examine the effects of active craniocervical movement training using a cognitive game on stroke patient's cervical movement control ability, balance, and functional mobility. Methods: The subject of this study were 29chronic stroke patients who were randomly allocated to either an experimental, cognitive game group (n = 15), or control group (n = 14), to which only neuro-developmental treatment (NDT) was applied. The intervention was conducted 5 times per week, 30 minutes per each time, for a total of 4 weeks. Active angle reproduction test, static stability test, limits of stability test, and Time up and Go (TUG) test, respectively, were carried out in order to evaluate cervical movement control ability, static balance, dynamic balance, and functional mobility. Paired t-test was used in order to compare differences between prior to after the intervention, along with an independent-test in order to compare prior to and after-intervention differences between the two groups. Results: After the craniocervical training with a body-driven cognitive game, the experimental group showed significant differences in flexion, extension, and lateral flexion on the affected side, and rotation on the affected side in the active angle reproduction test. The experimental group indicated significant differences in sway length both with eyes-open and with eyesclosed in the static stability test and in limits of stability test and TUG test. The control group to which NDT was applied had significant differences in flexion in the active angle reproduction test and in limits of stability test and TUG test. Conclusion: The above results mean that craniocervical training using a body-driven cognitive game positively influences stroke patient's cervical movement control ability and as a result their balance and functional mobility.