• Journal of Welding and Joining
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• v.18 no.5
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• pp.49-54
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• 2000

High speed rotating arc process, forming a flat bead surface with shallow penetration depth, can be applied to the automatic seam tracking, because the amplitude of current waveform increases at high rotation speed. Two high speed arc rotation mechanisms have been developed in Japan and Germany b rotating the electrode nozzle using an external motor, which are used prevalently for narrow gap and conventional seam welding. In this study, a new rotation mechanism was developed by using a hallow shaft motor designed to be installed in the electrode nozzle. By rotating the welding arc, the amplitude of current waveform increases remarkably since the self-regulation of arc is not fully performed. Experiments show that the arc sensor with high-speed rotation arc has improved its responsiveness and sensitivity.

• The Journal of Korean Physical Therapy
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• v.30 no.1
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• pp.23-28
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• 2018

Purpose: This study examined the effectiveness of iliopsoas self-stretching on the hip extension angle, gluteus maximus (GM) activity, and pelvic compensated angle during prone hip extension (PHE) in subjects with iliopsoas shortness. Methods: Twenty-healthy subjects with iliopsoas shortness were recruited. Electromyography (EMG) was used to examine erector spinae (ES), multifidus (MF), GM, and biceps femoris (BF) while performing PHE. An electromagnetic tracking motion analysis device was used to measure the pelvic compensations. The pelvic compensations while performing PHE were considered to be anterior tilting and rotation. A modified Thomas test was used to monitor the hip extension angle before and after iliopsoas self-stretching. A paired t-test was used to investigate the significant difference after iliopsoas self-stretching during PHE. The level of statistical significance was set to ${\alpha}=0.05$. Results: Muscle activity of GM and hip extension angle were significantly greater after iliopsoas self-stretching compared to that before iliopsoas self-stretching during PHE (p<0.05). BF and pelvic rotation angle were significantly lower after iliopsoas self-stretching compared to that before iliopsoas self-stretching during PHE (p<0.05). The muscle activity of ES was not significantly different between PHE before and after iliopsoas self-stretching (p>0.05). Conclusion: Iliopsoas self-stretching can be effective in selectively strengthening the GM muscles with minimized pelvic compensation in subjects with iliopsoas shortness.

• Journal of the Korean Geophysical Society
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• v.9 no.2
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• pp.99-103
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• 2006

3D object recognition independent of translation and rotation using an ultrasonic sensor array, invariant moment vectors and SOFM(Self Organizing Feature Map) neural networks is presented. Using invariant moment vectors of the acquired 16×8 pixel data of square, rectangular, cylindric and regular triangular blocks, 3D objects could be classified by SOFM neural networks. Invariant moment vectors are constant independent of translation and rotation. The recognition rates for the training and testing data were 95.91% and 92.13%, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.590-593
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• 2021

본 연구에서는 목발을 사용하는 교통약자가 물품을 안정적으로 휴대할 수 있도록 도와주는 장치를 개발하였다. 2축 짐벌 구조를 기반으로 서보모터, IMU센서, 아두이노 나노 마이크로프로세서로 구현하였고, Pitch와 Roll 방향 회전을 상쇄하기 위해 센서 각도를 변환 없이 사용하는 기본제어법과 PID 제어법을 사용하여 비교하였다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.11
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• pp.609-615
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• 2000

A prototype electrodeless sulfur lamp was developed and investigated the spectroscopic characteristics. The emission spectra of $S_2$ in the microwave-discharged eletrodeless sulfur lamp (ESL) were studied at various input power. The emission spectra of the ESL shift to longer wavelength with increasing of the input power. We have shown that this is due to the self reversal effect in the high pressure gas discharge. We also show that the self reversal effect increases as the rotation of the discharged bulb. The spectral distribution of the ESL shifts about 45 nm toward visible region from UV region due to the rotation of the lamp bulb.

• Current Applied Physics
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• v.18 no.11
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• pp.1261-1267
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• 2018

In this paper, an off-axis digital holographic microscopy compensated with self-hologram rotation is presented. The process is implemented via subtracting the unwrapped phase maps of the off-axis parabolic hologram and its rotation $180^{\circ}$ to eliminate the tilt induced by the angle between the spherical object wave O and the plane reference wave R. Merit of the proposed method is that it can be done without prior knowledge of physical parameters and hence can reconstruct a parabolic hologram of $1024{\times}768$ pixels within tens of milliseconds since it doesn't require a digital reference wave. The method is applied to characterize rough gold bumps and the obtained results were compared with those extracted from the conventional reconstruction method. The comparison showed that the proposed method can characterize rough surfaces with excellent contrast and in realtime. Merit of the proposed method is that it can be used for monitoring smaller biological cells and micro-fluidic devices.

• Korean Journal of Occupational Health Nursing
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• v.21 no.2
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• pp.154-163
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• 2012

Purpose: The purpose of study was to identify the relationships among attitude on job rotation, job stress and organizational commitment of hospital nurses. Methods: The data were collected from the self-reported questionnaire responses of 430 nurses from Sep. 1 to Sep. 30, 2010 at a university hospital in D city and analyzed by descriptive statistics, t-test, ANOVA, Scheff$\acute{e}$ test and Pearson correlation coefficients. Results: Nurses who experienced job rotation showed negative attitude on job rotation (t=-4.84, p<.001), high level of job stress (t=3.81, p<.001) and low level of organizational commitment (t=-1.99, p= .047). There was a significantly negative correlation between nurses' attitude on job rotation and job stress (r=-.13, p<.01). Also, there was a significantly positive correlation between nurses' attitude on job rotation and organizational commitment (r=.32, p<.001). Conclusion: These results suggest that job rotation in nurses needs to be planned based on the individual attitude, opinion, specialty and capability in nurse for reducing their job stress and enhancing organizational commitment of hospital nurses.

• Journal of Korean Academy of Nursing Administration
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• v.10 no.4
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• pp.459-472
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• 2004

This study was designed to investigate perception of job rotation and an organizational commitment of staff nurses working at K hospital and find the way of increasing an organizational commitment for the groundwork for efficient changes in the nursing staff. Data were collected from Aug. 20 to Aug. 28, 2004 through self reporting questionnaires taken by 318 nurses working at a hospital. The three structured instruments were used for collecting the data; Questionnaires for measuring the perception of job rotation, Questionnaires for measuring the utility and the problem of job rotation, and Mowday's Organizational Commitment Questionnaires. The Results were as follows : 1. 66.0% of 318 staff nurses approved of regular job rotation; 34.0% of them disapproved 34.3% of them wanted to get transferred to another department; 65.7% of them didn't. 2. Of general characteristics, age(F=17.469, P=.000), marital status(F=-2.781, P=.006), religion(F=5.688, P=.001), education level(F=8.816, P=.000), position(F=15.591, P=.000), a total clinical career(F=11.606 p=.000) and field in practice(F=4.206, P=.000) were significantly related to an organizational commitment. 3. There is relatively positive correlation between the perception of job rotation and an organizational commitment. In conclusion, the utility of on the job rotation and organizational commitment showed the positive correlation.

• Journal of The Korean Astronomical Society
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• v.25 no.2
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• pp.67-78
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• 1992

Effects of cloud rotation 011 the profiles of CO J=$1{\rightarrow}0$ lines arc investigated by theoretically general ing line profiles under physical conditions similar to t he ones in large globules. The synthesized profiles are presented and their characteristics are discussed. It is found that when the Doppler shift of the observed CO lines is interpreted as the rotation velocity, the optically thin $^{13}CO$ lines underestimate the rotation velocity by up to 10 percents, while the self-reversed optically thick $^{12}CO$ lines overestimate the velocity up to 20 percents. The optically thin line is shown to be of use in probing the distribution of rotation velocity in dark globules.

• Advances in concrete construction
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• v.8 no.3
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• pp.187-198
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• 2019

Torsional behaviors of beams are investigated for the web reinforcement and the concrete type. Eight beams with self-compacting concrete (SCC) and twelve beams with conventional concrete (CC) were manufactured and tested. All the models manufactured as the $250{\times}300{\times}1500mm$ were tested according to relevant standards. Two concrete types, CC and SCC were designed for 20 and 40 MPa compressive strength. From the point of web reinforcement, the web spacing was chosen as 80 and 100 mm. The rotation angles of the concrete beams subjected to pure torsional moment as well as the cracks occurring in the beams, the ultimate and critical torsional moments were observed. Moreover, the ultimate torsional moments obtained experimentally were compared with the values evaluated theoretically according to some relevant standards and theories. The closest estimations were observed for the skew-bending theory and the Australian Standard.