• Journal of information and communication convergence engineering
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• v.12 no.2
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• pp.104-108
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• 2014

The field of body sensor networks has attracted interest of many researchers due to its potential to revolutionize medicine. These sensors are usually implanted inside the human body and communicate among themselves. In the process of receiving, processing, or transmitting data, these devices produce heat. This heat damages the tissues surrounding the devices in the case of prolonged exposure. In this paper, to reduce this damages, we have improved and evaluated two protocols-the least temperature routing protocol and adaptive least temperature routing protocol-by implementing clustering as well as a leadership rotation algorithm. We used Castalia to simulate a basic body area network cluster composed of 6 nodes. A throughput application was used to simulate all the nodes sending data to one sink node. Simulations results shows that improved communication protocol with leadership rotation algorithm significantly reduce the energy consumption as compared to a scheme without leadership rotation algorithm.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1087-1090
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• 2007

A wireless magnetic torque sensor is utilized to measure the torque generated in the rotating shaft in magnetic field without connecting to the shaft by any wire. In this study, a new wireless magnetic torque sensor was introduced. The structure of the sensor was explained detailed as well as its operation principle. Resulting from the torque measurement experiment results, the sensor was proven to measure the generated torque effectively. Compared with traditional contact torque sensor, the wireless one has low cost and good environment adaptation ability. Moreover, the intractable wrapping wires around the shaft are removed in this design. Hence the wireless torque sensor may be expected as a possible sensing device for many applications, such as the electric assisting rotation system in automobiles, the torque sensing system in motors, the arm rotation system in robotics and so on.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1682-1687
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• 2003

Die polishing technology is very critical to determine quality and performance of the final products. Generally, the rotation-type tool is used most widely in the polishing process. However it is difficult to make the mirror surface, because the method using the rotation-type tool causes a lot of tiny scratch on the polished surface. This paper proposes a new method using the oscillation-type tool that reduces the scratch and improves the surface roughness. As result. the mirror surface was able to obtain by using the oscillation-type tool. AE is known to be closely related to material removal rate(MRR). As the surface is rougher, MRR gets larger and AE increase. The surface roughness can be indirectly estimated using the AE signal measured during automatic die polishing process. In this study. an AE sensor based monitoring system was developed to investigate the relation the level of AE RMS with the surface roughness during polishing process.

• 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.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.3
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• pp.183-191
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• 2016

Recently, in rehabilitation treatment, the situation that requires a measure of the accuracy of the pose and movement of joints is being increased due to the habits and lifestyle of modern people and the environment. In particular, there is a need for active automated system that can determine itself for the matching rate of pose Basically, a method for measuring the matching rate of pose is used by extracting an image using the Kinect or extracting a silhouette using the imaging device. However, in the case of extracting a silhouette, it is difficult to set the comparison, and in the case of using the Kinect sensor, there is a disadvantages that high accumulated error rate according to movement. Therefore, In this paper, we propose a method to reduce the accumulated error of matching rate of pose getting the rotation angle of joint by measuring the real-time amount of change of 9-axis sensor. In particular, it can be measured same conditions that unrelated of the physical condition and unaffected by the data for the back and forth movement, because of it compares the current rotation angle of the joint. Finally, we show a comparative advantage results by compared with traditional method of extracting a silhouette and a method using a Kinect sensor.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.95-101
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• 2020

We studied the Implementation and design of inertial sensor that enables to improve performance by reduce the noise of rotor which Angle of inclination. Analyze model equation including motion equation and error, signal processing filter algorithm on high frequency bandwidth with eliminates error using estimation of error coefficient method is was designed and the prototype inertial sensor showed the pick off noise up to 0.2 mV and bias error performance of about 0.06 deg/hr by the experiments. Accordingly, we confirmed that the design of inertial sensor was valid for high rotation.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.771-778
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• 2006

Before the Flap type GATE is introduced until, the Turnstile type GATE was plentifully used. The Turnstile type GATE is used plentifully from the Seoul metro, Busan Transportation Corporation and Korea Railroad Corporation. From the Turnstile type GATE, the micro switch breakdown is occurred by the contact of the micro switch which perceives a Turnstile rotation and the cam. The breakdown is cause of the passenger inconveniently. In order to prevent the breakdown which is caused by Micro switch contact, Microswitch support used the sensor in Turnstile rotation perception. The sensor which is used in test is Photo Sensor and Reed Sensor two type. The test result Reed Sensor was suitable in underground environment. When using the RF card, RF card processing came to be quick

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.1020-1022
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• 2014

In this paper, we present a method for smartphone users to have a better user experience when playing 3D mobile games using the gyro sensor. We designed the rotation of the virtual camera in the game world to be proportional to the real-world's rotation. We have also made the sensitivity configuration possible for users to manipulate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.285-293
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• 2017

Jump rope has two motions. It starts as hand motion and ends as jump motion. Therefore, two motions should be considered together to detect rotations accurately. But previous researches only consider one of the two motions as in push-up, sit-up, lift dumbbells etc, which results in inaccurate detection of rotations. In this paper, detection of rotation in jump rope using two motions through 6-axis accelerometer gyro sensor is proposed. Jump motion is detected using accelerometer sensor and hand motion is detected using gyro sensor. Also start point and end point of jump rope is detected using magnitude and standard deviation of accelerometer and gyro sensor values. The count of rotation is detected using y-axis of gyro sensor value. Y-axis of gyro sensor value indicate hand motion of jump rope motion. The usefulness of the proposed method is confirmed through experimental results.

• PNF and Movement
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• v.19 no.1
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• pp.1-8
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• 2021

Purpose: The purpose of this study was to determine how the position of tibial rotation affects peak force and hamstring muscle activation during isometric knee flexion in healthy women. Methods: Seventeen healthy women performed maximum isometric knee flexion at 30˚ with three tibial rotation positions (tibial internal rotation, neutral position, and tibial external rotation). Surface electromyographic (EMG) activity was recorded from the medial hamstring (MH) and lateral hamstring (LH) muscles. The strength of the knee flexor was measured with a load-cell-type strength-measurement sensor. Data were analyzed using one-way repeated analysis of variance. Results: The results showed that MH and LH activities and peak force were significantly different among the three tibial rotation conditions (p < 0.01). The post-hoc comparison revealed that the MH EMG activity in tibial neutral and internal rotation positions were significantly greater than tibial external rotation (p < 0.01). The LH activity in tibial external rotation was significantly greater than the tibial neutral position and internal rotation (p < 0.01). The peak force of the knee flexor was also greater in the external tibial rotation position compared with the tibial neutral and internal rotation positions (p < 0.01). Conclusion: Our findings suggest that hamstring muscle activation could be changed by tibial rotation.