• The Journal of Korean Physical Therapy
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• v.17 no.4
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• pp.621-631
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• 2005

The purpose of this study was to measure magnitude of lower leg muscle activity during dynamic stability tests performed on an unstable board by subjects with sprained lateral ankles. Fifteen lateral ankle sprain subjects(8 male, 7 female) participated in this study. The muscle activity was measured at gastrocnemious, tibialis anterior, peroneus longus during dynamic stability tests performed on Biodex stability system as surface EMG. The EMG amplitude of each muscle was normalized to the amplitude in the maximal voluntary isometric contraction(MVIC) of each muscle. As results, peroneus longus evidenced significant difference at stable and unstable grade comparing injured with uninjured sides. Gastrocnemious and tibialis anterior evidenced no significant difference. Change of muscle activity with stable and unstable grade evidenced no significant difference on injured and uninjured sides. The data provided information on peroneus longus contributes to dynamic stability after lateral ankle sprains. Peroneus longus training program may have to be emphasized after an ankle sprain.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.7
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• pp.646-654
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• 2010

This paper describes an integrated chassis control for a maneuverability, a lateral stability and a rollover prevention of a vehicle by the using of the ESC and AFS. The integrated chassis control system consists of a supervisor, control algorithms and a coordinator. From the measured and estimation signals, the supervisor determines the vehicle driving situation about the lateral stability and rollover prevention. The control algorithms determine a desired yaw moment for lateral stability and a desired longitudinal force for the rollover prevention. In order to apply the control inputs, the coordinator determines a brake and active front steering inputs optimally based on the current status of the subject vehicle. To improve the reliability and to reduce the operating load of the proposed control algorithms, a multi-core ECU platform is used in this system. For the evaluation of this system, a closed loop simulations with driver-vehicle-controller system were conducted to investigate the performance of the proposed control strategy.

• Structural Engineering and Mechanics
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• v.19 no.6
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• pp.679-705
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• 2005

This paper presents a practical method to evaluate the effective length factors for columns in multi-storey unbraced frames based on the concept of storey-based elastic buckling by means of decomposing a multi-storey frame into a series of single-storey partially-restrained (PR) frames. The lateral stiffness of the multi-storey unbraced frame is derived and expressed as the product of the lateral stiffness of each storey. Thus, the stability analysis for the multi-storey frame is conducted by investigating the lateral stability of each individual storey, which is facilitated through decomposing the multi-storey frame into a series of single-storey PR frames and applying the storey-based stability analysis proposed by the authors (Xu and Liu 2002) for each single-storey PR frame. Prior to introducing decomposition approaches, the end rotational stiffness of an axially load column is derived and rotational stiffness interaction between the upper and lower columns is investigated. Three decomposition approaches, characterized by means of distributing beam-to-column rotational-restraining stiffness between the upper and lower columns, are proposed. The procedure of calculating storey-based column effective length factors is presented. Numerical examples are then given to illustrate the effectiveness of the proposed procedure.

• Steel and Composite Structures
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• v.15 no.2
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• pp.175-202
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• 2013

The super convergent laminated composite beam element is newly derived for the lateral stability analysis. For this, a theoretical model of the laminated composite beams is developed based on the first-order shear deformation beam theory. The present laminated beam takes into account the transverse shear and the restrained warping induced shear deformation. The second-order coupling torque resulting from the geometric nonlinearity is rigorously derived. From the principle of minimum total potential energy, the stability equations and force-displacement relationships are derived and the explicit expressions for the displacement parameters are presented by applying the power series expansions of displacement components to simultaneous ordinary differential equations. Finally, the member stiffness matrix is determined using the force-displacement relationships. In order to show accuracy and superiority of the beam element developed by this study, the critical lateral buckling moments for bisymmetric and monosymmetric I-beams are presented and compared with other results available in the literature, the isoparametric beam elements, and shell elements from ABAQUS.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.228-233
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• 2001

In this case study, under conideration of field situations, such as increase of water level, height increment of the marine structure, dredging and backfill, the stability analysis of sliding and lateral flow of the marine structure in OOOharbor was carried out, and foundation reinforcement methods was presented. based on the results of site investigation, the stability analysis of slope sliding and lateral flow was performed as following. In section BH-1, 2, the analysis was performed in two cases that the marine structure was heightened and filled, and not heightened and filled. In section BH-1, 4, heightened and filled. The analysis results showed that the stabilities of slope sliding and lateral flow in section BH-1, 2, 3, 4 were unstable. After additional reinforcements with Deep Mortar Pile, the stabilities in section BH-1, 2, 3, 4 were evaluated as efficiently large.

• Structural Engineering and Mechanics
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• v.6 no.2
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• pp.161-172
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• 1998

Reinforced concrete beams possess variable flexural and torsional stiffnesses due to formation of cracks in the tension area along the beam. In order to check the stability of the beam, it is thus more appropriate to divide the beam into a finite number of segments for which mean stiffnesses and also bending moments are calculated. The stability analysis is further simplified, by using these mean values for each segment. In this paper, an algorithm for calculating the critical lateral buckling slenderness ratio for a definite load level, in a reinforced concrete beam without lateral support at the flanges, is presented. By using this ratio, the lateral buckling safety level of a slender beam may be checked or estimated.

• International Journal of Railway
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• v.3 no.4
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• pp.126-133
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• 2010

The thermal buckling analysis of curved continuous welded rail (CWR) is studied for the lateral buckling prevention. This study includes a thermal buckling theory which accounts for both thermal and vehicle loading effects in the evaluation of track stability. The parameters include rail size, track lateral resistance, track longitudinal and torsional stiffnesses, initial misalignment amplitude and wavelength, track curvature, tie-ballast friction coefficient and truck center spacing. Parametric studies are performed to evaluate the effects of the individual parameters on the upper and lower critical buckling temperatures. The results show that the upper critical buckling temperature is highly affected by the uplift due to vehicle loads. This study provides a guideline for the improvement of stability for dynamic buckling in curved CWR track.

• Journal of the Korean Society for Precision Engineering
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• v.7 no.3
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• pp.103-114
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• 1990

Many high speed mechanical systems incorporate gearing for speed reduction. This study investigates the stability of mulit-rotor geared systems supported on oil film bearings taking into consideration the coupling between torsional and lateral dynamics. The emphasis of the study is on the analysis of the interaction between the combined torsional and whirl insta- bilities. The feasility of inducing a lateral and the torsional instability to neutralize an anticipated unstable condition is investigated. The possibility of suppressing the instabilities by controlling the parameters of the oil film bearings is also considered.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.2
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• pp.132-140
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• 2010

Purpose: The aim of this study is to identify the usefulness of unilateral mandibular angle ostectomy, so-called "Lateral Angle Reduction", in asymmetric prognathism patients by the assessment of postoperative stability and esthetic results Patients and methods: For the retrospective study, 10 skeletal class III mandibular asymmetry patients who were performed SSRO and unilateral mandibular angle ostectomy, Lateral Angle Reduction, was selected. Lateral and posterioanterior cephalogram was taken before surgery (T0), 1day after surgery (T1) and 6month after surgery (T2). To know the esthetic results the facial width and lateral facial contour were examined on posterioanterior cephalogram and to know the postoperative stability B point and Incisor inferius was examined on lateral cephalogram. Statistical analysis was performed. Results: From T0 to T1, Intergonial width was significantly decreased, dominantly at shortened side but no significant changes at lengthened side. Those were well-maintained during 6 months. Lateral facial angle and Ramus angle was significantly decreased on only shortened side from T0 to T1. As a result, after surgery, there were no significant differences in all measurements between shortened side and lengthened side. Ramus deviation angle in shortened side and ramus angle in lengthened side which reflect the angulation of ramus on frontal plane didn't show significant changes after surgery and during postsurgical periods. Lower dental midline showed no statistical changes during postsurgical period. The relapse rate on B-point was 11.92%. Conclusion: Unilateral "Lateral angle reduction" in the asymmetric mandible is valuable to obtain the narrow lower face and symmetric facial contour with a good stability.

• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.899-910
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• 2013

This paper presents a novel lateral stability control system for electric vehicle based on sideslip angle estimation through Kalman filter using the integration of a single antenna GPS receiver and yaw rate sensor. Using multi-rate measurements including yaw rate and course angle, time-varying parameters disappear from the measurement equation of the proposed Kalman filter. Accurate sideslip angle estimation is achieved by treating the combination of model uncertainties and external disturbances as extended states. Active front steering and direct yaw moment are integrated to manipulate sideslip angle and yaw rate of the vehicle. Instead of decoupling control design method, a new control scheme, "two-input two-output controller", is proposed. The extended states are utilized for disturbance rejection that improves the robustness of lateral stability control system. The effectiveness of the proposed methods is verified by computer simulations and experiments.