• Journal of Magnetics
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• v.17 no.4
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• pp.285-290
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• 2012

Electric Power Steering (EPS) system is superior to conventional Hydraulic Power Steering (HPS) system in aspect of fuel economy and environmental concerns. The EPS system consists of torque sensor, electric motor, ECU (Electric Control Unit), gears and etc. Among the elements, the torque sensor is one of the core technologies of which output signal is used for main input of EPS controller. Usually, the torque sensor has used torsion bar to transform torsion angle into torque and needs linear characteristic in terms of flux variation with respect to rotation angle of permanent magnet. The torsion angle of both ends of a torsion bar is measured by a contact variable resistor. In this paper, the sensor is accurately analyzed using 3D finite element method and its characteristics with respect to four different shapes of the stator teeth are compared. The four shapes are rectangular, triangular, trapezoidal and circular type.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.702_703
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• 2009

Electric Power Steering(EPS) system is superior to conventional Hydraulic Power Steering(HPS) system in aspect of fuel economy and environmental concerns. The EPS system consists of torque sensor, electric motor, ECU(Electric Control Unit), gears and etc. Among the elements, the torque sensor is one of the core technologies of which output signal is used for main input of EPS controller. Usually, the torque sensor has used torsion bar to transform torsion angle into torque. The torsion angle of both ends of a torsion bar is measured by a contact variable resistor. In this paper, the sensor is accurately analyzed using 3D finite element method and its characteristics with respect to four different shapes of the stator teeth are compared. The four shapes are rectangular, triangular, trapezoidal and circular type.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.4
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• pp.339-345
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• 2014

PURPOSE: This study is to investigate the effect of 4 weeks of gym ball exercise on the pelvis and spine of women in 20s. METHODS: Randomly selected 10 of 20 subjects are allocated to experimental group who will practice gym-ball exercise while the rest 10 subjects are allocated to control group. Values for pelvic obliquity DL-DR, pelvic torsion DL-DR, pelvic rotation, kyphotic angle ICT-ITL (max), and lordotic angle ITL-ILS (max) were measured through recording using 3-dimensional image analyzer as a preliminary inspection. Gym-ball exercise was implemented 3 sessions a week for 4 weeks. Each session consisted of 10 minutes of warm up exercise, 30 minutes of main exercise, and 10 minutes of cool down exercise totaling 50 minutes. Post inspections were measured after exercise. RESULTS: Experimental group showed statistically significant difference in pelvic obliquity DL-DR, pelvic torsion DL-DR, and kyphotic angle ICT-ITL (max) (p<.05) and values of pelvic obliquity DL-DR showed statistically significant difference between two groups (p<.05). However pelvic rotation, lordotic angle ITL-ILS (max) did not show a significant difference. CONCLUSION: These results showed that gym-ball exercise has positive effect in the pelvic obliquity, torsion and spine kyphotic angle and expected to have positive effect on the body balance, body lineup, and coordination.

• Journal of the Korean Orthopaedic Association
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• v.55 no.1
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• pp.62-70
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• 2020

Purpose: External tibia torsion and proximal tibial vara have been reported in severe varus deformed osteoarthritis, which is a tibio-femoral angle of more than 20°. The radiology measurements were compared with those of control group and the preoperative and follow-up radiology and clinical results were examined. Materials and Methods: From January 2007 to March 2016, 43 knees from 37 persons, who underwent total knee arthroplasty for a severe varus deformity of more than 20° on the tibio-femoral angle on the standing radiographs and had a follow-up period more than two years, were examined. The mean follow-up period was 45.7 months. The control group, who underwent conservative treatments, had Kellgren-Lawrence grade three osteoarthritis and a tibio-femoral angle of less than 3° varus. The external tibial torsion of enrolled patients and control group were estimated using the proximal tibio-fibular overlap length and the tibial torsion values on computed tomography. The proximal tibia vara was measured using the proximal tibial tilt angle. The preoperative and postoperative proximal tibio-fibular overlap length, tibial torsion value, proximal tibial tilt angle, and hospital for special surgery (HSS) score were evaluated. Results: The mean proximal tibio-fibular overlap length was 18.6 mm preoperatively and 11.2 mm (p=0.031) at the follow-up. The control group had a mean proximal tibio-fibular overlap length of 8.7 mm (p=0.024). The mean tibial torsion value was 13.8° preoperatively and 14.0° (p=0.489) at the follow-up. The control group had a mean tibial torsion value of 21.9° (p=0.012). The mean proximal tibial tilt angle was 12.2° preoperatively and 0° (p<0.01) at the follow-up. The control group had a mean proximal tilt angle of 1.2° (p<0.01). The preoperative tibiofemoral angle and mechanical axis deviation were corrected from preoperative 28.3° and medial 68.4 mm to postoperative 0.7° and medial 3.5 mm (p<0.01, p<0.01), respectively. The HSS scores increased from 34 points of preoperatively to 87 points at the last follow-up (p=0.028). Conclusion: Patients with advanced osteoarthritis with a severe varus deformity of more than 20° had significant increases in the external tibial torsion and varus of the proximal tibia. The tibial torsion value before and after surgery in the enrolled patients was not changed statistically, but good clinical results without complications were obtained.

• Structural Engineering and Mechanics
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• v.62 no.5
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• pp.577-585
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• 2017

To study the mechanical performances of prestressed steel-concrete composite box beam under combination of bending-shear-torsion, nine composite beams with different ratio of torsion to bending were designed. Torsion was applied to the free end of the beam with jacks controlled accurately with peripherals, as well as concentrated force on the mid-span with jacks. Based on experimental data and relative theories, mechanical properties of composite beams were analyzed, including torsional angle, deformation and failure patterns. The results showed that under certain ratio of torsion to bending, cracking and ultimate torsion increased and reached to its maximum at the ratio of 2. Three phases of process is also discussed, as well as the conditions of each failure mode.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.195-202
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• 1999

The kinematic and complicance characteristics of torsion beam axle is structurally related to the location and section profile of torsion beam and the span from body mounting point to wheel center. This paper presents the effect of section properties in torsion beam on the structural characteristics and roll behavior of suspension. The structural characteristics is on the maximum stress on the welding area of torsion beam and the roll behavior is on roll steer and roll-camber of suspension which are important for controllability and stability in cornering. Four factors are used for the section design of torsion beam, which are thickness , midline length, are inner radius, and sector half angle . Through the structural and quasi-static analysis made for six torsion beam axle models, it can be noticed that roll steer and the structural durability of suspension are closely related to warping constant and shear center in section properties of torsion beam.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1103-1108
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• 2001

ACI 318-99 predicts the torsional moment of reinforced concrete members by assuming that the angle of diagonal compressive concrete is equal to 45 degree. However, this angle depends on the difference of longitudinal and transverse steel ratios. This paper compares the torsional moments calculated by ACI 318-99 code and a truss model considering compatibility of strains. The comparison indicated that the torsion equation in ACI code underestimated the real torsional moment of reinforced concrete beam in which the ratio of longitudinal reinforcement was larger than that of transverse reinforcement.

• Transactions of Materials Processing
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• v.32 no.6
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• pp.376-383
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• 2023

The torsion bar, which is a steering torque sensor, is mounted between the steering pinion and the input shaft in the IPA(input pinion assembly). Accurate torque measurement is important to improve the sense of operation, and the straightness of the torsion bar can affect torque measurement. In this study, the amount of bending was measured and the exact shape was analyzed regarding the bending phenomenon in the press-fitting process for torsion bars. The effect of alignment error was analyzed through finite element forming analysis. Process data analysis was conducted for the double-end press fit model. If there is an alignment error of about 10% of the serration tooth height, the indentation load is reduced by about 10%. If there is an alignment error, the torsion bar is rotated.

• Advances in materials Research
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• v.13 no.2
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• pp.87-102
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• 2024

This paper is focused on the delamination analysis of a multilayered beam structure loaded in torsion under strain-path control. The beam under consideration has a rectangular cross-section. The layers of the beam are made of different viscoelastic materials which exhibit continuous inhomogeneity in longitudinal direction. Since the delamination is located inside the beam structure, the torsion moments in the two crack arms are obtained by modeling the beam as an internally static undetermined structure. The strain energy stored in the beam is analyzed in order to derive the strain energy release rate (SERR). Since the delamination is located inside the beam, the delamination has two tips. Thus, solutions of the SERR are obtained for both tips. The solutions are verified by analyzing the beam compliance. Delamination analysis with bending-torsion coupling is also performed. The solutions derived are timedependent due to two factors. First, the beam has viscoelastic behavior and, second, the angle of twist of the beam-free end induced by the external torsion moment changes with time according to a law that is fixed in advance.

• Journal of the Semiconductor & Display Technology
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• v.3 no.3
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• pp.27-29
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• 2004

The responses of hypothetical silicon nanotubes under torsion have been investigated using an atomistic simulation based on the Tersoff potential. A torque, proportional to the deformation within Hooke's law, resulted in the ribbon-like flattened shapes and eventually led to a breaking of hypothetical silicon nanotubes. Each shape change of hypothetical silicon nanotubes corresponded to an abrupt energy change and a singularity in the strain energy curve as a function of the external tangential force, torque, or twisted angle. The dynamics of silicon nanotubes under torsion can be modelled in the continuum elasticity theory.