• Journal of Institute of Control, Robotics and Systems
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• v.10 no.7
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• pp.611-617
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• 2004

This paper presents a simple method of rotational motion estimation and correction for roll axis stabilization of an image. The scheme first computes the rotation center by taking least squares of selected local velocity vectors, and the rotational angle is found from special subset of motion vectors. Roll motion correction is then performed by the nearest neighbor interpolation technique. To show the effectiveness of our approach, the synthetic and real images are evaluated, resulting in better performance than the previous ones.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.42-44
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• 2003

The paper presents the method and apparatus for conformal photoresist spray coating on the 3D structured substrate. The system consists of a high-temperature-rotational chuck, ultrasonic spray nozzle module, angle control module and nozzle moving module. The coating uniformity is acquired by controlling the moving speed of the ultrasonic spray nozzle across the substrate which is rotated constantly. To coat the photoresist conformally the spray angle of the nozzle and the temperature of the substrate are controlled during spray coating. The rotational chuck can be heated up by hot air or $N_2$. The photoresist (AZ1512) has been coated on the 3D structured wafer by spray coating system and the characteristics have been evaluated.

• The Journal of Advanced Prosthodontics
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• v.9 no.4
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• pp.278-286
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• 2017

PURPOSE. The aim of this study was to determine the influence of long base lengths of a fixed partial denture (FPD) to rotational resistance with variation of vertical wall angulation. MATERIALS AND METHODS. Trigonometric calculations were done to determine the maximum wall angle needed to resist rotational displacement of an experimental-FPD model in 2-dimensional plane. The maximum wall angle calculation determines the greatest taper that resists rotation. Two different axes of rotation were used to test this model with five vertical abutment heights of 3-, 3.5-, 4-, 4.5-, and 5-mm. The two rotational axes were located on the mesial-side of the anterior abutment and the distal-side of the posterior abutment. Rotation of the FPD around the anterior axis was counter-clockwise, Posterior-Anterior (P-A) and clockwise, Anterior-Posterior (A-P) around the distal axis in the sagittal plane. RESULTS. Low levels of vertical wall taper, ${\leq}10-degrees$, were needed to resist rotational displacement in all wall height categories; 2-to-6-degrees is generally considered ideal, with 7-to-10-degrees as favorable to the long axis of the abutment. Rotation around both axes demonstrated that two axial walls of the FPD resisted rotational displacement in each direction. In addition, uneven abutment height combinations required the lowest wall angulations to achieve resistance in this study. CONCLUSION. The vertical height and angulation of FPD abutments, two rotational axes, and the long base lengths all play a role in FPD resistance form.

• Korean Journal of Applied Biomechanics
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• v.21 no.1
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• pp.39-46
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• 2011

The purpose of this study was to examine differences between players who bend the left elbow and those who stretch it during the forward swing from BST to BC in a 2-handed backhand stroke among outstanding high school tennis players, and to assess the detailed 3D rotational kinematic characteristics of the shoulder and the hip. Statistically significant differences were observed between groups in the longitudinal axis rotation angle of the shoulder and the angle between the shoulder and the arm at BST, and in the side to side movement of the shoulder, the up and down movement of the hip, the side tilt angular velocity of the shoulder, the side tilt angular velocity of the hip, and the front tilt angular velocity of the hip at BC. The difference in the longitudinal axis rotation angle of the shoulder between the 2 groups suggests a difference in the flexibility of the joint in the shoulder arm racquet system. The longitudinal axis rotation angular velocity of the shoulder reached its peak at 75 % of the duration of the analyzed segment and then decreased little by little until BC. This time is considered the stage for increasing the angular velocity of the upper arm, the forearm, the hand and then the racquet, which are more distal segments than the shoulder.

• Journal of Korea Foundry Society
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• v.24 no.5
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• pp.273-280
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• 2004

Vibrational motions of the compaction table were investigated to select the optimal operation conditions of sand filling and compaction for the EPC process. Their modes were measured at the nine points of the table with changing the relative rotation angles between the two eccentric mass vibrators which were attached parallel beneath the table. Well-defined vibration modes were measured at the center of the table but those of left and right sides of the table were distorted regardless of rotational angle differences. The distortion of vibration modes at both sides of the table were caused by the moment generated by offset positions of two eccentric masses. It was found that the uniform vibration modes would be gathered by controlling the relative distances between the rotating axis and the center of gravity in the compaction system at the various conditions of vibration modes and rotational angle differences.

• The KSFM Journal of Fluid Machinery
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• v.13 no.1
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• pp.23-28
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• 2010

A draft tube which has impeller to elevate bottom water and spread it over surface of lake water, induces convective circulation of lake water, a Long-Distance Circulation (LDC). Circulation of lake water make stratified water mixed and enhance DO (Dissolved Oxygen) of bottom water. Circulation rate of water is determined by draft rate of the tube, which is dependent on design parameters of the draft tube system, i. e. dimension of impeller and diffuser, inclined angle of impeller, impeller shape, and rotational speed. In this study, change in draft rate and power consumption of circulation equipment was investigated numerically with changing impeller dimension, angle and rotational speed. It was found that flowrate of draft water was increased as the dimensions of draft tube and impeller, and rotational speed and inclined angle of impeller increased. The power consumption was also elevated with increasing parameter values, and final selection of parameter values was made to satisfy target flowrates and power consumption.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1901-1905
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• 2004

A controller designed by CDM for a servo type system which is an augmented system constructed from a rotational inverted pendulum with an integrator added to its arm, is presented in this paper. In order to be able to apply the CDM concept, the augmented system must be linearized and converted into controllable canonical form. Then, the controller consisting of the state feedback gain matrix and an integral gain in the sense of CDM can be obtained. This shows that design procedure for the proposed controller is easy. The experimental results obtained from the rotational inverted pendulum controlled by the proposed controller show that the system response has no steady-state error, however, the oscillation amplitude of the arm angle is still significant. Therefore, in this paper, the friction compensation using Coulomb friction with stiction is also added to the controller. The oscillation amplitude of the arm angle that can be reduced remarkably is also shown in the experimental results.

• Journal of KIISE:Software and Applications
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• v.31 no.4
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• pp.411-419
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• 2004

When the imaging object rotates in image plane during MRI scan, its rotation causes phase error and non-uniform sampling to MRI signal. The model of the problem including phase error non-uniform sampling of MRI signal showed that the MRI signals corrupted by rotations about an arbitrary center and the origin in image plane are different in their phases. Therefore the following methods are presented to improve the quality of the MR image which includes the artifact. The first, assuming that the angle of 2-D rotational motion is already known and the position of 2-D rotational center is unknown, an algorithm to correct the artifact which is based on the phase correction is presented. The second, in case of 2-D rotational motion with unknown rotational center and unknown rotational angle, an algorithm is presented to correct the MRI artifact. At this case, the energy of an ideal MR image is minimum outside the boundary of the imaging object to estimate unknown motion parameters and the measured energy increases when the imaging object has an rotation. By using this property, an evaluation function is defined to estimate unknown values of rotational angle at each phase encoding step. Finally, the effectiveness of this presented techniques is shown by using a phantom image with simulated motion and a real image with 2-D translational shift and rotation.

• Journal of Industrial Technology
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• v.17
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• pp.305-312
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• 1997

Shear connections in steel structures should satisfy dual criteria of shear strength and rotational flexibility and ductility. The connection should be strong enough to transfer the shear reaction of the beam, and should have sufficient rotational flexibility and ductility to rotate easily and supply the end rotation demand of the beam. This paper is concerned with the behavior of double-angle shear connections where the parameters are numbers of high strength bolts, bolt pitch, the length of angle leg, and connection method. An experimental investigation of shear connection was conducted by testing 12 beam-to-column joint specimens. Based on experimental and analytical study, the failure modes are developed and proposed design formulas.

• Structural Engineering and Mechanics
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• v.58 no.6
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• pp.1001-1020
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• 2016

The study is to investigate the free vibration of antisymmetric angle-ply conical shells having non-uniform sinusoidal thickness variation. The arbitrarily varying thickness is considered in the axial direction of the shell. The vibrational behavior of shear deformable conical shells is analyzed for three different support conditions. The coupled differential equations in terms displacement and rotational functions are obtained. These displacement and rotational functions are invariantly approximated using cubic spline. A generalized eigenvalue problem is obtained and solved numerically for an eigenfrequency parameter and an associated eigenvector of spline coefficients. The vibration characteristic of the shells is examined for cone angle, aspect ratio, sinusoidal thickness variation, layer number, stacking sequence, and boundary conditions.