• International Journal of Highway Engineering
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• v.15 no.1
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• pp.65-73
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• 2013

PURPOSES: This paper presents the results of computer simulations of roadside safety barrier, called by safety roller guardrail, consisting of rotational roller, rotation control plate, post and subsidiary members. The rotation roller and rotation control plate are made by EVA(ethylene vinyl acetate), and PE(polyester), respectively. METHODS: The occupant risk analysis has been carried out under vehicle crash condition for high containment level of SB-4 for the purpose of local road. Simulations are performed with the finite element code LS/DYNA-3D. RESULTS: The numerical results obtained by LS/DYNA-3D software from the viewpoints of vehicle stability, vehicle trajectory, occupant risk, etc. CONCLUSIONS: It is noted that not only impact severity is drastically reduced but also vehicle trajectory is improved due to the characteristics of energy absorption and rotation pattern of EVA rollers connected by control plates.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.3
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• pp.605-613
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• 2009

In this paper, we studied for the real-time azimuthal measurement of HMD (Head Mounted Display) to control the tele-operated vision system on the mobile robot. In the preexistence tele-operated vision system, a joystick was used to control the pan-tilt unit of the remote camera system. To give the sense of presence to the tele-operator, we used a HMD to display the remote scene, measured the rotation angle of the HMD on a real time basis, and transmitted the measured rotation angles to the mobile robot controller to synchronize the pan-tilt angles of remote camera with the HMD. In this paper, we suggest an algorithm for the real-time estimation of the HMD rotation angles using feature points extraction from pc-camera image. The simple experiment is conducted to demonstrate the feasibility.

• The Journal of Korean Physical Therapy
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• v.30 no.5
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• pp.166-172
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• 2018

Purpose: This study compared the different sling and resistance exercises on pelvic rotation during active straight leg raises (ASLR) and on pain in patients with chronic low back pain (CLBP). Methods: Twenty subjects were divided randomly into a sling group (SG) and a resistance exercise group (REG). Internal oblique (IO), external oblique (EO), rectus abdominis (RA), and rectus femoris (RF) muscle activity; pelvic rotation angle during ASLR; and visual analogue scale, pressure pain threshold were measured. Sling and resistance exercises were then performed for 30 minutes and the measurements taken again. Results: Both groups showed significantly lower RF muscle activity and significantly higher EO and IO muscle activity (p<0.05). The RA muscle activity decreased significantly in the SG, but increased significantly in the REG (p<0.05). The pelvic rotation angle was significantly lower in the SG (p<0.05). The pain press threshold increased significantly in both groups (p<0.05). The visual analogue scale decreased significantly in the SG (p<0.05). Conclusion: Both exercises appear to be beneficial for modifying the muscle activity and pain control in the intervention of CLBP. On the other hand, the sling was more effective in increasing the pressure threshold than resistance exercise, and the pelvic rotation angle was reduced. Therefore, both exercises can help patients with CLBP change their muscle activity and control pain. CLBP patients should use a sling for short periods of time to learn to reduce the pain and control pelvic rotation.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.5
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• pp.376-382
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• 2000

A problem of relevant interest to some industries is that of the optimum two-dimensional layout. In this problem, one is given a number of rectangular sheets and an order for a specified number of each of certain types of two-dimensional regular and irregular shapes. The aim is to cut the shapes out of the sheets in such a way as to minimize the amount of waste produced. In this paper, we propose a genetic algorithms using rotation parameters by which the best pattern of layout is found.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.6-11
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• 1988

Alight-weight robot arm carrying a payload is modelled as a cantilever beam with a tip mass subjected to a high speed rotation. Equations of Motion, for modal control, are represented as discrete state variable form. Digital optimal control law with observer is developed to suppress the arm vibration and control the position of the joint angle. The effects of the number of controlled modes, weighting factors of the performance index, reference rotation time, and sampling time on the control performance are analyzed by computer simulation and experiments.

• Korean Journal of Acupuncture
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• v.17 no.1
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• pp.47-65
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• 2000

The meridian, the meridian point and the Acupuncture-Bu-Xie(鍼灸補瀉) of oriental medicine are very important in the Department of Acupuncture and Moxibustion. Until now it has been confused at the practical use, and it showed up many transformation to the ages and many scholars. And then, I made a study of effects on the thermal changes of Sangyang($LI_1$,商陽), Igan($LI_2$,二間), Samgan($LI_3$,三間), Hapkok($LI_4$,合谷), Yanggye($LI_5$,陽谿), Kokchi($LI_{11}$,曲池), Yonghyang($LI_{20}$,迎香) following acupuncture on the Hapkok with the Rotated Acupuncture-Bu-Xie(捻轉補瀉) stimulation. This study researched into clinical statistics for 140 men who are in good health, and they are studying oriental medicine at Woosuk university in Korea. This study was covered a period of 3 months form June, 1999 to August, 1999. The objective was divided into seven groups, those are the control group(CON, N=20), the acupuncture stimulation group with non-rotation on Hapkok of left hand(A-I, N=20), the acupuncture stimulation group with non-rotation on non-meridian point(NA) of left hand(A-II, N=20), the acupuncture stimulation group with Bu-rotation(捻轉補法) on Hapkok of left hand(B-I, N=20), the acupuncture stimulation group with Bu-rotation on non-meridian point(NA) of left hand(B-II, N=20), the acupuncture stimulation group with Xie-rotation(捻轉瀉法) on Hapkok of left hand(C-I, N=20), and the acupuncture stimulation group with Xie-rotation on non-meridian point of left hand(C-II, N=20). The first, I took a picture for 140 men with the Digital infrared thermal image(D.I.T.I.). After 10 minutes, I took a second picture for each group following experimental methods, those were followed acupuncture on the Hapkok and the non-meridian point with the retentive and Rotated Acupuncture-Bu-Xie stimulation. The results are summarized as follows : 1. The thermal changes of the area which is a meridian point in the Large Intestine Meridian of the acupuncture stimulation group on Hapkok different from the control groups with significantly change. 2.The thermal changes of the area which is a meridian point in the Large Intestine Meridian of acupuncture stimulation groups on non-meridian point was not significantly different from the control group. 3. The thermal changes of the area which is a meridian point in the Large Intestine Meridian of the acupuncture stimulation group with Bu-rotation on Hapkok different from the control group with significant increase. 4. The thermal changes of the area which is a meridian point in the Large Intestine Meridian of acupuncture stimulation group with Bu-rotation on non-meridian point was not significantly different from the control group. 5. The thermal changes of the area which is a meridian point in the Large Intestine Meridian of the acupuncture stimulation group with Xie-rotation on Hapkok different from the control group with significant decrease and increase following the decreasing or increasing temperature class, and the increasing temperature class of the acupuncture stimulation group with Xie-rotation on Hapkok significantly different from the acupuncture stimulation group with Bu-rotation on Hapkok. 6. The thermal changes of the area which is a meridian point in the Large Intestine Meridian of acupuncture stimulation group with Xie-rotation on non-meridian point was not significantly different from the control group. As a conclusion, I could think that the acupuncture stimulation with Bu-rotation or Xie-rotation on Hapkok affected the thermal change of the area which is a meridian point in the Large Intestine Meridian. And then I could relate these results with the existence of the meridian and meridian point, and with the Rotated Acupuncture-Bu-Xie theory of oriental medicine.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.2
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• pp.300-314
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• 2017

This paper examines finite rotation angle (FRA) applications for spacecraft attitude control. The coordinate transformation matrix and the attitude kinematics represented by FRAs are introduced. The interpolation techniques for the angular orientations are thoroughly investigated using the FRAs and the results are compared to those using traditional methods. The paper proposes trajectory description techniques by using extremely smooth polynomial functions of time, which can describe point-to-point attitude maneuvers in a realizable and accurate manner with the help of unique FRA features. In addition, new controller design techniques using the FRAs are developed by combining the proposed interpolation techniques with a model predictive control framework. The proposed techniques are validated through their attitude control applications for an aggressive point-to-point maneuver. Conclusively, the FRAs provide much more flexibility than quaternions and Euler angles when describing kinematics, generating trajectories, and designing attitude controllers for spacecraft.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.115-118
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• 1995

This paper present an attitude control using quaternions as feedback attitude errors. The Euler's eigenaxis rotation provides the shortest angular path between two attitudes. This eigenaxis rotation can be achieved by using quaternions since quaternions are related with the eigenaxis. The suggested controller uses error quaternions and body angular rates and generates a decoupling control torque that counteracts the natural gyroscopic coupling torque. The momentum dumping strategy using the earth magnetic field is also applied in this paper to unload the angular momentum of the reaction wheels used in the attitude control.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1371-1376
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• 1990

The paper presents a method of constructing simple fuzzy control rules for the determination of stabilizing signals of automatic voltage regulator and governor, which are controllers of electric power systems. Fuzzy control rules are simplified by considering a coordinate transformation with the rotation angle .theta. on the phase plane, and by expanding the range of membership functions. Also, two rotation angles .theta. $_{1}$ and .theta. $_{2}$ are selected for the linearizable region and the nonlinear one of the system, respectively. Here, .theta. $_{1}$ is chosen by the pole assignment method, and .theta. $_{2}$ by a performance index. Fuzzy inference is applied to the connection of two rotation angles .theta. $_{1}$ and .theta. $_{1}$ by regarding the distance from the desired equilibrium point as a variable of condition parts. The control effect is demonstrated by an application of the proposed method to one-machine infinite-bus power system.

• Journal of the Ergonomics Society of Korea
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• v.32 no.2
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• pp.199-205
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• 2013

Objective: The aim of this study is to investigate the job rotation implementation at medium- or small-industries and to identify the viewpoint on job rotation as preventive activity of work-related musculoskeletal disorders(WMSDs). Background: Job rotation has been implemented in many industrial areas in order to prevent the WMSDs as one part of ergonomic program. Generally, the cases of implementation of ergonomic program or successful cases of job rotation were reported on the side of major or large company. Therefore, this study tried to inspect the current state of job rotation implementation at medium- or small-industries. Method: Survey was carried out for randomly contacted forty seven mangers responsible for safety. Survey contained the questionnaires on the general state of company, shift-work and job rotation. Results: The ratio of work-shift in medium- and small-industry was 34.0% and the ratio of job rotation was 19.1%. For manufacturing industry, the ratio was 37.9% and 17.2%, respectively. Conclusion: The implementation ratio of job rotation was relatively low considering the results of previous studies. Many managers appealed the quality decreasing of goods and the injuries of workers due to job rotation, though agreed to train the multi-functional worker and to prevent the WMSDs. Application: The results can be used for the fundamental data how the job rotation will be properly implemented in medium- and small-industry as an administrative control for MSDs.