• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.5
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• pp.453-457
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• 2006

This study was designed to investigate the effect of intra-articular injection of hyaluronic acid for the treatment of internal derangements of the temporomandibular joint(TMJ). Sixteen patients with internal derangements of TMJ in 1 male and 15 females aged 68 to 18 years comprised the study material. The patients' complaint was limited mouth opening and pain during function. Patients were divided into 3 groups(articular disc displacement with reduction, articular disc displacement without reduction, osteoarthritis group). The preauricular area was disinfected anesthetized locally with 2% lidocaine hydrochloride. Arthrocentesis was performed. Hyaluronic acid(1.5 ㏄) was then injected into the superior compartment of the TMJ. Active range of motion exercises were instituted at approximately 24 hours postoperatively. Antibiotics and NSAID, three times daily by mouth, was prescribed for 3 days. Clinical evaluation of the patients was done before the procedure, immediately after the procedure, final follow-up visit postoperatively. Pain during function was assessed using visual analog scales(VAS). Maximal mouth opening was recorded as a distance between upper incisal edge and lower incisal edge. Intra-articular injection of hyaluronic acid caused significant reduction of pain during function, significant increase of maximal opening range. These findings suggest that intra-articular injection of hyaluronic acid is useful for decreasing patient reports of pain while increasing functional mobility of the mandible in internal derangements of the TMJ.

• Smart Structures and Systems
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• v.8 no.5
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• pp.433-447
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• 2011

The present paper addresses the nonlinear response of a FG square plate with two smart layers as a sensor and actuator under pressure. Geometric nonlinearity was considered in the strain-displacement relation based on the Von-Karman assumption. All the mechanical and electrical properties except Poisson's ratio can vary continuously along the thickness of the plate based on a power function. Electric potential was assumed as a quadratic function along the thickness direction and trigonometric function along the planar coordinate. By evaluating the mechanical and electrical energy, the total energy equation can be minimized with respect to amplitude of displacements and electrical potential. The effect of non homogenous index was investigated on the responses of the system. Obtained results indicate that with increasing the non homogenous index, the displacements and electric potential tend to an asymptotic value. Displacements and electric potential can be presented in terms of planar coordinate system. A linear analysis was employed and then the achieved results are compared with those results that are obtained using the nonlinear analysis. The effect of the geometric nonlinearity is investigated by using the comparison between the linear and nonlinear results. Displacement-load and potential-load curves verified the necessity of a nonlinear analysis rather than a linear analysis. Improvement of the previous results (by the linear analysis) through employing a nonlinear analysis can be presented as novelty of this study.

• Journal of KSNVE
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• v.7 no.2
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• pp.247-254
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• 1997

In the case of a precision equipment, it requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga class semiconductor wafers. This high technology equipments require very strict environmental vibration standard in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria are usually obtained either by the real vibration exciting test on the equipment or by the analytical calculation. This paper proposes a new method to solve this problem at a time. The permissible vibration level to a precision equipment can be easily obtained by analyzing a process of Frequency Response Function. This paper also demonstrates its effectiveness by applying the proposed method to finding the vibration criteria of a Computer Hard Disk Driver by Impact Test.

• Journal of International Academy of Physical Therapy Research
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• v.9 no.4
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• pp.1663-1668
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• 2018

This study was conducted to examine the effects of Evjenth-Hamberg stretching of the sternocleidomastoid, upper trapezius, and pectoralis major on the lung function of adults with forward neck posture. The subjects were 20 adult students in P university located in Pohang, Korea, whose degree of head forward displacement measured according to NEW YORK state posture test was mild. The subjects were randomly and equally assigned to the Evjenth-Hamberg Stretching group (EHSG, n=10) and the control group (CG, n=10). Their forced vital capacity (FVC), slow vital capacity (SVC), and maximal voluntary ventilation (MVV) were measured before and after the experiment. In within-group comparison, only the EHSG experienced statistically significant improvement in FVC, forced expiratory volume in the first second (FEV1), and peak expiratory flow (PEE) after the experiment, compared to before the experiment (.05

• Structural Engineering and Mechanics
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• v.18 no.2
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• pp.247-262
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• 2004

In the earlier application of the spline finite strip method(FSM), the uniform B3-spline functions were used in the longitudinal direction while the conventional interpolation functions were used in the transverse direction to construct the displacement filed in a strip. To overcome the shortcoming of the uniform B3-spline, non-periodic B-spline was developed as the displacement function. The use of non-periodic B3-spline function requires no tangential vectors at both ends to interpolate the geometry of shell and the Kronecker delta property is also satisfied at the end boundaries. Recently, non-periodic spline FSM which was modified to have a multiple knots at the boundary was developed for the shell analysis and applied to the analysis of bridges. In the formulation of a non-symmetric spline finite strip method, the concepts of non-periodic B3-spline and a stress-resultant finite strip with drilling degrees of freedom for a shell are used. The introduction of non-symmetrically spaced knots in the longitudinal direction allows the selective local refinement to improve the accuracy of solution at the connections or at the location of concentrated load. A number of numerical tests were performed to prove the accuracy and efficiency of the present study.

• Structural Engineering and Mechanics
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• v.71 no.2
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• pp.197-210
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• 2019

Probabilistic buckling behavior of sandwich panel considering random system parameters using a radial basis function (RBF) approach is presented in this paper. The random system properties result in an uncertain response of the sandwich structure. The buckling load of laminated sandwich panel is obtained by employing higher-order-zigzag theory (HOZT) coupled with RBF and probabilistic finite element (FE) model. The in-plane displacement variation of core as well as facesheet is considered to be cubic while transverse displacement is considered to be quadratic within the core and constant in the facesheets. Individual and combined stochasticity in all elemental input parameters (like facesheets thickness, ply-orientation angle, core thickness and properties of material) are considered to know the effect of different degree of stochasticity, ply- orientation angle, boundary conditions, core thickness, number of laminates, and material properties on global response of the structure. In order to achieve the computational efficiency, RBF model is employed as a surrogate to the original finite element model. The stiffness matrix of global response is stored in a single array using skyline technique and simultaneous iteration technique is used to solve the stochastic buckling equations.

• The Journal of Korean Physical Therapy
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• v.24 no.5
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• pp.291-299
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• 2012

Purpose: This study examined the improved sensory, hand function, postural balance and activities of daily living (ADL) through somatosensory stimulation, such as the facilitation of functional reaching and tactile, proprioceptive stimulus of the upper limb (UL) and hand. Methods: Seventeen stroke patients having problems with motor and somatosensory deficits were selected in Bobath Memorial Hospital adult rehabilitation center. The patients were divided into two groups; the sensorimotor deficit group (SMDG) and motor deficit group (MDG). Somatosensory stimulation on the UL, physical therapy and occupational therapy were carried out three times a week over a six week these treatments were performed in both group period. To compare each group, the following assessment tools were used: such as tactile detection thresholds (TDT), two point discrimination on the affected side (TPDas), unaffected side (TPDus) stereognosis (ST) manual function test, hand function on the affected side (HFas) and unaffected side (HFus), Postural Assessment Scale for Stroke (PASS) and Korean version Modified Barthel Index (K-MBI). Results: In the SMDG, somatosensory stimulation on the UL was statistically important for TDT, TPDas, TPDus (except for the thener), ST, hand function on HFas, on HFus, PASS length of displacement with foam (LDFSEO), and K-MBI. In the MDG, somatosensory stimulation on the UL was important for TDT, TPDas, TPDus (except index finger) length of displacement with the eyes open, LDFSEO, HFas, HFus, PASS and K-MBI. In addition, there was a significant difference in the PASS between SMDG and MDG. Conclusion: Somatosensory stimulation on the UL affects the sensory, hand function, postural control and ADLs performance.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.2
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• pp.96-108
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• 2022

In this paper, we propose a systematic hull form variation technique which automatically satisfies the displacement constraint and guarantees a high level of fairness. This method is possible through multiple parameter correction curves. The present method is to improve the hull form variation method based on parametric modification function and consists of two sub-categories: SAC variation and section lines modification. For SAC variation, the utilization of two B-Spline curves satisfying GC¹ condition led to the satisfaction of displacement constraint and high level of fairness at the same time. Section lines modification methods involves in using two fuctions: the first is the waterplane modification function combining two cubic splines. the other function is the sectional area modification function consisting of 2nd order polynomial over the DLWL(Design Load Waterline) and 3rd order polynomial below the DLWL, This function enables not only the fundamental U-V section shape variation but also systematically modified section lines. The present method is expected to be more useful in the hull form optimization process using CFD compared to the existing method.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.156-159
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• 2003

Surface normal vector and surface velocity are very important parameters to simulate rolling processes precisely. In this study, Local displacement functions are constructed for each node on the contact surface and parameters are found by the least square fitting of displacement on the neighbor nodes. Deformation gradient tensor is calculated from the displacement function and surface normal vector and velocity also can be derived. Flat rolling simulation model is presented on the basis of the suggested contact scheme. Series of rolling process simulation are carried out and the results are compared with the experiments.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.43-52
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• 2010

In this study, the shapes of the wheel and rail are represented by using 3-dimensional surface functions with surface parameters and a 3-dimensional wheel-rail contact analysis is presented. A whole numerical solution of wheel-rail contact at tread and flange including 2-point contacts can be achieved with the proposed numerical algorithm. Kinematic characteristics such as variances of vertical displacement and roll angle, and variance of wheel radius difference for arbitrary yaw and lateral displacement of wheelset, are determined for the KTX wheel-rail pair as an example. The condition of yaw and lateral displacement occurring 2-point contacts to analyze derailment are compared between standard and worn wheels. Differences of contact characteristics between curved and straight rails are also analyzed.