• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.1316-1319
• /
• 1996

This paper proposes the algorithm for the correction of a position and orientation of small object such as chip in the precise construction process. In the past, it is general to correct position and orientation of object using human sight and simple vision sensors. But recently, researches using image processing devices have been studied to improve the corrective precision of a position and orientation of object. In this piper, maximum-axis moment and p-theta algorithm are used to correct the position and orientation. Algorithm of maximum-axis moment is widely applied to hetero-object except being applied to a perfect rectangle. This is reason that moments of the X and Y-axis are equal. Therefore, being the shape of a perfect rectangle, the object is applied to other algorithm. In the light of time problem, real-time control is as important as correction of object. To solve it, we use the DSP(Digital Signal Processing) which is far more fast than PC.

• Structural Engineering and Mechanics
• /
• v.38 no.6
• /
• pp.825-847
• /
• 2011

This paper investigates the design using wind-moment method for semi-rigid un-braced steel frames bending on weak axis. A limiting sway method has been proposed to reduce the frame sway. Allowance for steel section optimization between moment of inertia on minor axis column and major axis beam was used in conjunction with slope-deflection analysis to derive equations for optimum design in the proposed method. A series of un-braced steel frames comprised of two, four, and six bays ranging in height of two and four storey were studied on minor axis framing. The frames were designed for minimum gravity load in conjunction with maximum wind load and vice-versa. The accuracy of the design equation was found to be in good agreement with linear elastic computer analysis up to second order analysis. The study concluded that the adoption of wind-moment method and the proposed limiting sway method for semi-rigid steel frame bending on weak axis should be restricted to low-rise frames not more than four storey.

• Structural Engineering and Mechanics
• /
• v.56 no.5
• /
• pp.745-765
• /
• 2015

This paper presents the design of reinforced concrete combined footings of trapezoidal form subjected to axial load and moments in two directions to each column using a new model to consider soil real pressure acting on the contact surface of the footing; such pressure is presented in terms of an axial load, moment around the axis "X" and moment around the axis "Y" to each column. The classical model considers an axial load and moment around the axis "X" (transverse axis) applied to each column, and when the moments in two directions are taken into account, the maximum pressure throughout the contact surface of the footing is considered the same. The main part of this research is that the proposed model considers soil real pressure and the classical model takes into account the maximum pressure, and also is considered uniform. We conclude that the proposed model is more suited to the real conditions and is more economical.

• Korean Journal of Applied Biomechanics
• /
• v.28 no.4
• /
• pp.227-236
• /
• 2018

Objective: The purpose of this study was to investigate the effects of a 12-week combined exercise program on gait parameters in elderly women with osteoarthritis. Method: The subjects of this study were 11 elderly women (age: $67.09{\pm}2.47$, height: $157.35{\pm}4.30cm$, weight: $62.49{\pm}6.36kg$) with knee osteoarthritis. The combined exercise program of this study was divided into aerobic exercise and lower extremity strengthening exercises. The exercises were performed for 60 minutes per session, three times a week, for a total of 12 weeks. The maximum joint moments of the hip, knee, and ankle joints with walking were obtained with 8-3D cameras (MX-T20, Vicon, USA) and 2-force plate (AMTI OR6-7-400, AMTI, USA). SPSS Windows version 23.0 was used for statistical analysis. A paired t-test was used for pre-post comparison. An alpha level of .05 was utilized in all tests. Results: The maximum extension moment was significantly higher in the hip joint after P1 on the X axis. The maximum joint moment of P3 in extension was statistically significantly lower after intervention. On the Z axis, the maximum joint moment was significantly lower after the exercise intervention at P3. There was a statistically significant increase in the extension moment of the left and right knee joints in the X axis after exercise intervention. In the right ankle joint, P1 (plantar flexion moment) showed a statistically significant high moment after exercise intervention. Conclusion: These results suggest that combined exercise, including lower limb and aerobic exercise, may have a positive effect on mobility and walking moments in patients with osteoarthritis of the knee.

• Journal of Institute of Control, Robotics and Systems
• /
• v.15 no.6
• /
• pp.612-618
• /
• 2009

This study is concerned about the optimal design of the arm 1 and arm 2 in the SCARA robot. The mass and inertia moment of the arm I and arm 2 in a SCARA robot is greatly affected on the performance such as a cycle time, and torques loaded on $1^{st}$ axis and $2^{nd}$ axis. To reduce the mass and inertia moment, this study carried out optimal design by FEM analysis using parametric variables, which is a width, a height of the rib and a thickness of arm in the arm. The rib is adapted instead of reducing the thickness in the arm. And the simulation by computer was conducted on two given paths in X direction and Y direction. After optimal design, the result showed that maximum torque of $1^{st}$ axis and $2^{nd}$ axis reduced to maximum 9.5% on a given path.

• Journal of Sensor Science and Technology
• /
• v.20 no.5
• /
• pp.351-356
• /
• 2011

Stroke patients should exercise for the rehabilitation of their fingers, because they can't use their hand and fingers. Their hand and fingers are fixed on the hand fixing system for rehabilitation exercise of them. But the hands clenched the fist of stroke patients are difficult to fix on it. In order to fix the hands and fingers, their palms are pressed with pressing bars and are controlled by reference force. The fixing system must have a five-axis force/moment sensor to force control. In this paper, the five-axis force/moment sensor was developed for the hand fixing system of finger-rehabilitation exercising system. The structure of the five-axis force/moment sensor was modeled, and designed using finite element method(FEM). And it was fabricated with strain-gages, then, its characteristic test was carried out. As a result, the maximum interference error is less than 2.43 %.

• Geomechanics and Engineering
• /
• v.14 no.1
• /
• pp.61-69
• /
• 2018

The first part shows the optimal contact surface for T-shaped combined footings to obtain the most economical dimensioning on the soil (optimal area). This paper presents the second part of a new model for T-shaped combined footings, this part shows a the mathematical model for design of such foundations subject to axial load and moments in two directions to each column considering the soil real pressure acting on the contact surface of the footing with one or two property lines restricted, the pressure is presented in terms of an axial load, moment around the axis "X" and moment around the axis "Y" to each column, and the methodology is developed using the principle that the derived of the moment is the shear force. The classic model considers an axial load and a moment around the axis "X" (transverse axis) applied to each column, i.e., the resultant force from the applied loads is located on the axis "Y" (longitudinal axis), and its position must match with the geometric center of the footing, and when the axial load and moments in two directions are presented, the maximum pressure and uniform applied throughout the contact surface of the footing is considered the same. To illustrate the validity of the new model, a numerical example is presented to obtain the design for T-shaped combined footings subjected to an axial load and moments in two directions applied to each column. The mathematical approach suggested in this paper produces results that have a tangible accuracy for all problems.

• Computers and Concrete
• /
• v.20 no.2
• /
• pp.129-143
• /
• 2017

Seismic design of reinforced concrete (RC) structures requires a certain minimum level of flexural ductility. For example, Eurocode EN1998-1 directly specifies a minimum flexural ductility for RC beams, while Chinese code GB50011 limits the equivalent rectangular stress block depth ratio at peak resisting moment to achieve a certain nominal minimum flexural ductility indirectly. Although confinement is effective in improving the ductility of RC beams, most design codes do not provide any guidelines due to the lack of a suitable theory. In this study, the confinement for desirable flexural ductility performance of both normal- and high-strength concrete beams is evaluated based on a rigorous full-range moment-curvature analysis. An effective strategy is proposed for flexural ductility design of RC beams taking into account confinement. The key parameters considered include the maximum difference of tension and compression reinforcement ratios, and maximum neutral axis depth ratio at peak resisting moment. Empirical formulae and tables are then developed to provide guidelines accordingly.

• Journal of Korean Society of Steel Construction
• /
• v.20 no.4
• /
• pp.483-491
• /
• 2008

There has been much focus on the strong axis steel moment connections after the Northridge earthquake in 1994. However, research studieson the seismic behavior of weak axis moment connections could be hardly found despite the fact that these connection details have been frequently used as seismic details of MRF in Korea. Therefore, the objective of this research is to provide better knowledge on the seismic behavior of weak-axis steel moment connections, which can be widely applicable to many structures with similar characteristics. For this purpose, an experimental program was designed and performed with twotypes of weak-axis steel moment connections, namely the bracket type and WUF-B type, based on the survey of existing field data and literatures. Using the experimental results obtained from the quasi-static cyclic testing of these specimens, structural performances of the joints such as hysteretic curves, maximum strength capacities and the strain of reinforced bars were investigated. From the test results, the bracket-type connection was shown to have more than a 5% story drift capacity, compared with the WUF-B type connection's 4%. These specimens were also shown to have higher strength capacities than the nominal design strength. The bracket-type connection showed a slow strength degradation after maximum strength was researched. However,the WUF-B type connection showed a rapid strength degradation that caused brittle behavior.

• Steel and Composite Structures
• /
• v.30 no.2
• /
• pp.109-121
• /
• 2019

This paper presents the second part of the modeling for the strap combined footings, this part shows a mathematical model for design of strap combined footings subject to axial load and moments in two directions to each column considering the soil real pressure acting on the contact surface of the footing for one and/or two property lines of sides opposite restricted, the pressure is presented in terms of an axial load, moment around the axis "X" and moment around the axis "Y" to each column, and the methodology is developed using the principle that the derived of the moment is the shear force. The first part shows the optimal contact surface for the strap combined footings to obtain the most economical dimensioning on the soil (optimal area). The classic model considers an axial load and a moment around the axis "X" (transverse axis) applied to each column, i.e., the resultant force from the applied loads is located on the axis "Y" (longitudinal axis), and its position must match with the geometric center of the footing, and when the axial load and moments in two directions are presented, the maximum pressure and uniform applied throughout the contact surface of the footing is considered the same. A numerical example is presented to obtain the design of strap combined footings subject to an axial load and moments in two directions applied to each column. The mathematical approach suggested in this paper produces results that have a tangible accuracy for all problems and it can also be used for rectangular and T-shaped combined footings.