• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.351.2-351
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• 2001

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3158-3163
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• 2013

In this study, squeal noise test was conducted by using the lab-scaled brake dynamometer. Squeal conditions with respect to the angle of the brake pads ($34^{\circ}30^{\circ}26^{\circ}$) and negative slope, were studied. Squeal frequency of the In-plane-like mode was confirmed by hammering test and finite element analysis. This Squeal mode was difficult to control by the pad angle variation. Also the squeal sound was found to be periodic signal which has higher harmonic components. Squeal noise is independent of the negative slope. It implies that squeal noise can reach the stick-slip oscillation.

• The Korean Journal of Zoology
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• v.27 no.3
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• pp.127-136
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• 1984

The specification of dorsal/ventral axis in the egg of Xenopus laevis was investigated as a series of oblique orientation to gravity by tilt and clinostat. The results are as follows. (1) If the eggs were oriented, in the early period after fertilization, to novel gravity by $15^\\circ, 30^\\circ, 45^\\circ$ and $60^\\circ$ tilt until gastrula stage, the site of involution was usually formed in the OpG side (the side opposing gravity). As the degree of tilt was raised from $15^\\circ to 60^\\circ$, the rate of relocation of the involution site was proportionally increased. (2) When UV-irradiated eggs were tilted period to first cleavage by $15^\\circ, 30^\\circ, 45^\\circ$ and $6\^\\circ$, the effect of UV syndrome was rescued, and the extent of rescue was propotional to the tilt degree. (3) The fertile eggs were loaded on the clinostats of several speeds. In the range of low speeds between $0.45 \\sim 9.0$ rph, the location of dorsal lip was dependent on the direction of rotation, and in $40 \\sim 360$ rph, lip was formed at a random position. In addition, some of the tadpoles experienced with clinostat showed the typical syndrome of "dorsal axis reduction". The above results were discussed regarding the mechanism of the establishment of dorsal/ventral palarity. palarity.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.591-596
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• 2022

Since 4-bar linkage widely used in various industrial fields has a fixed link length, it is inconvenient to add an independent link structure or control device to change the movement of output link. Therefore, this paper proposes a new concept of variable 4-bar linkage mechanism to selectively adjust the movement of the output link to fit desired situations, and applied to the commercial table fans, which is a representative product using a 4-bar linkage system. The optimal rotation angle steps for efficiency are determined experimentally and the appropriate lengths of linkage to fit each step are calculated analytically. Changes in the linkage length are implemented by the rotational motion using a grooved cylindrical cam and the feasibility of the proposed variable linkage mechanism is verified through fabrication and measurement. The presented variable link mechanism is expected to improve the efficiency of industrial robots and fuel valve systems.

• Journal of radiological science and technology
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• v.32 no.4
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• pp.419-426
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• 2009

Purpose : The aim of this study was to evaluate the difference of bone mineral density according to distal radius rotation and to develop the supporting tool to measure rotation angles. Materials and Methods : CT scanning and the measurement of BMD by DXA of the appropriate position of the forearm were performed on 20 males. Twenty healthy volunteers without any history of operations, anomalies, or trauma were enrolled. The CT scan was used to evaluate the cross sectional structure and the rotation angle on the horizontal plane of the distal radius. The rotational angle was measured by the m-view program on the PACS monitor. The DXA was used in 20 dried radii of cadaveric specimens in pronation and supination with five and ten degrees, respectively, including a neutral position (zero degrees) to evaluate the changes of BMD according to the rotation. Results : The mean rotation angle of the distal radius on CT was 7.4 degrees of supination in 16 cases (80%), 3.3 degrees of pronation in three cases (15%), and zero degree of neutral in one case (9%), respectively. The total average rotation angle in 20 people was 5.4 degrees of supination. In the cadaveric study, the BMD of the distal radius was different according to the rotational angles. The lowest BMD was obtained at 3.3 degrees of supination. Conclusion : In the case of the measurement of BMD in the distal radius with a neutral position, the rotational angle of the distal radius is close to supination. Pronation is needed for the constant measurement of BMD in the distal radius with the rotation angle measuring at the lowest BMD and about five degrees of pronation of the distal radius is recommended.

• Journal of the HCI Society of Korea
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• v.1 no.2
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• pp.27-33
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• 2006

This paper presents a new approach to translation and rotation invariant feature extraction for image texture retrieval. For the rotation invariant feature extraction, we invent angular projection along angular frequency in Polar coordinate system. The translation and rotation invariant feature vector for representing texture images is constructed by the averaged magnitude and the standard deviations of the magnitude of the Fourier transform spectrum obtained by the proposed angular projection. In order to easily implement the angular projection, the Radon transform is employed to obtain the Fourier transform spectrum of images in the Polar coordinate system. Then, angular projection is applied to extract the feature vector. We present our experimental results to show the robustness against the image rotation and the discriminatory capability for different texture images using MPEG-7 data set. Our Experiment result shows that the proposed rotation and translation invariant feature vector is effective in retrieval performance for the texture images with homogeneity, isotropy and local directionality.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1686-1694
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• 2014

In this paper, a new scheme to recognize a finger shape in the depth image captured by Kinect is proposed. Rigid transformation of an input finger shape is pre-processed for its robustness against the shape angle of input fingers. After extracting contour map from hand region, observing the change of contour pixel location is performed to calculate rotational compensation angle. For the finger shape recognition, we first acquire three pixel points, the most left, right, and top located pixel points. In the proposed algorithm, we first acquire three pixel points, the most left, right, and top located pixel points for the finger shape recognition, also we use geometrical features of human fingers such as Euclidean distance, the angle of the finger and the pixel area of hand region between each pixel points to recognize the finger shape. Through experimental results, we show that the proposed algorithm performs better than old schemes.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.6
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• pp.519-530
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• 2011

The screw conveyor system installed in EPB Shield TBM chamber was manufactured in small scale for pilot test to investigate the tunnel muck hauling system that could control the earth pressure and support face thrust force. In this experimental study, there were three different test conditions that include screw angles, screw pitch, and screw RPM. Through analysis on test results based on the muck hauling amount per unit time from screw conveyor, the optimum conditions of screw conveyor were proposed to be efficiently performed by the muck processing system. Finally, this study provided the meaningful results such as optimum screw angle, screw RPM, and screw pitch for anti-reverse flow of muck hauling.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1135-1142
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• 2017

In this paper, we propose an algorithm that can automatically mix the screen and sound by tracking the change of the sound data according to the screen change so that the real sound can be implemented in the personal broadcasting service. Since the personal broadcasting service is often broadcasted lively, it should be convenient to have a real-time mixing. Through experiments, it was confirmed that the sound pressure changes in a wide range in the high frequency band related to the clarity for understanding according to the rotation angle change of the screen. Regression analysis of the sound pressure changes at 2kHz, 4kHz, and 8kHz, The attenuation change of sound pressure was observed at the slope of -1.17, the slope of -2.0, and the slope of -2.44 for each frequency. Therefore, these experiment results can be applied to the VR service. This study is expected to be useful data in the implementation of personal broadcasting service.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.47-53
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• 2015

This paper is to study applying for numerical analysis method for flow field, velocity and pressure of fuel on the low pressure pump using excavator. The pressure distribution of fuel pump certified the linear variation according to rotation angle of rotor. Especially, it knew the fact that the pressure in rotation angle $40^{\circ}$ appeared high outlet and low inlet of fuel pump. Also, this range angle can seek the fact that the leakage flow and velocity are the most increasing. And the more rotor rotation of fuel pump, the more mean outlet flow rate increased in linear. Whenever the gap size decrease with rotor and housing, the discharge flow rate could seek the approaching 0.0712kg/s that consider with theory discharge flow rate calculated from displacement between rotor gear and idle gear.