• Title/Summary/Keyword: High rotation sensibility

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Design of Fiber Optic Gyroscope for Sensing High Rotation (고속회전 감지 광섬유자이로 설계)

  • Do, Jae-Chul;Chong, Kyoung-Ho;Jo, Min-Sik;Song, Ki-Won;Moon, Hong-Key
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.6
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    • pp.551-555
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    • 2009
  • We studied the design of fiber optic gyroscope that enables to sense high rotation by extending the limit of rotation sensibility of fiber optic interferometer. Based on the digital serrodyne modulation technique, the signal processing of fiber optic gyroscope was designed and the prototype fiber optic gyroscope showed the high rotation sensibility up to ${\pm}3000[deg/sec]$ and scale factor performance of about 150[ppm] by the experiments. Accordingly, we confirmed that the design of fiber optic gyroscope was valid for high rotation.

[Retracted] Acquisition of 9th Grade Students' Conception of Earth's Rotation According to Individual Difference of the Spatial Sensibility ([논문 철회] 9학년 학생의 공간 능력 차이에 따른 지구자전 개념의 획득)

  • Lee, Kyung-Hoon;Lim, Jong-Ok
    • Journal of the Korean earth science society
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    • v.31 no.3
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    • pp.267-275
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    • 2010
  • The purpose of this study is to investigate student's Acquisition about the conception of the Earth Rotation between difference of their Spatial Sensibility. In this study, four students were selected out of 83 9th graders in Gwangju, Korea. The spatial sensibility test instrument was developed by the Korean Testing Center, and the test instruments of 'the movement of celestial bodies' were developed by Kim (1997). The results were as follows: Students with higher spatial sensibility understood precisely about the Earth's rotation in stereoscopic space. However, those with lower spatial sensibility failed to grasp the Earth's rotation and memorized it as fragmentary concepts. As for gender effect, male student with higher spatial sensibility explained the concepts clearly, while that with lower spatial sensibility has difficulty with the Earth's rotation in relation to the diurnal motion of celestial bodies. On the other hand, female student with higher spatial sensibility explained the concepts correctly in detail, while that with lower spatial sensibility had difficulty explaining the concepts in stereoscopic space. Therefore, students with higher spatial sensibility should be presented with problems in which they form their own solution. Those with lower spatial sensibility should be allowed to understand the phenomena intuitively. In developing teaching methods, female students should interact with the concepts in stereoscopic space directly, while male students should consider the celestial objects from various viewpoints. Then spatial sensibility in relation to the movement of celestial bodies would be expected to improve.

Relationship between Vestibuloocular Reflex and Autonomic Nerve Response in Adults (성인에서 전정안구반사를 이용한 평형감각과 자율신경반응의 관련성)

  • 김규겸;박현영;전희정;윤상대;박병림
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1999.03a
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    • pp.237-242
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    • 1999
  • The nature of the interactions between the vestibular and autonomic systems is complex and has not been fully defined. Vestibuloocular reflex induced by sinusoidal rotation and activity of the autonomic nerves in the heart were measured to investigate the interactions between the vestibular system and the autonomic nervous system in healthy adults. Eye movement induced by sinusoidal rotation of the whole body or optokinetic stimulation at 0.04 Hz was analyzed in gain, phase, and symmetry. EKG was measured during vestibular stimulation and analyzed in heart rate variability including mean R-R interval, standard deviation (SD) and coefficient of variance (CV) of R-R interval, and power spectrum of low frequency region (LF) and high frequency region (HF). Gain of eye movement was 0.65${\pm}$0.03 by ratatory stimulation, 0.70${\pm}$0.02 in optokinetic stimulation, 0.08${\pm}$0.02 in visual suppression, and 0.84${\pm}$0.04 in visual enhancement. In R-R interval, resting condition (control) was 0.82${\pm}$0.03 sec, and visual suppression showed significant increase and visual enhancement did significant decrease compared with control (p<0.01).CV was 0.06${\pm}$0.02 in control and visual enhancement increased significantly (p<0.05). In LF/HF control was 1.40${\pm}$0.23, which was not different from rotatory or optokinetic stimulation. But visual suppression decreased LF/HF significantly and visual enhancement increased significantly compared with control (p<0.01). These results suggest that degree of gain corresponds with LF/HF and increased gain in visual enhancement is deeply related to the activity of sympathetic nerves.

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Energy-Efficient Quorum-Based MAC Protocol for Wireless Sensor Networks

  • Annabel, L. Sherly Puspha;Murugan, K.
    • ETRI Journal
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    • v.37 no.3
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    • pp.480-490
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    • 2015
  • The reliability of sensor networks is generally dependent on the battery power of the sensor nodes that it employs; hence it is crucial for the sensor nodes to efficiently use their battery resources. This research paper presents a method to increase the reliability of sensor nodes by constructing a connected dominating tree (CDT), which is a subnetwork of wireless sensor networks. It detects the minimum number of dominatees, dominators, forwarder sensor nodes, and aggregates, as well as transmitting data to the sink. A new medium access control (MAC) protocol, called Homogenous Quorum-Based Medium Access Control (HQMAC), is also introduced, which is an adaptive, homogenous, asynchronous quorum-based MAC protocol. In this protocol, certain sensor nodes belonging to a network will be allowed to tune their wake-up and sleep intervals, based on their own traffic load. A new quorum system, named BiQuorum, is used by HQMAC to provide a low duty cycle, low network sensibility, and a high number of rendezvous points when compared with other quorum systems such as grid and dygrid. Both the theoretical results and the simulation results proved that the proposed HQMAC (when applied to a CDT) facilitates low transmission latency, high delivery ratio, and low energy consumption, thus extending the lifetime of the network it serves.

Postural Control During Virtual Moving Surround Stimulation in Patients with Brain Injury (뇌기능 장애 환자의 가상 환경 움직임(Virtual Moving Surround) 자극에 따른 자세 균형 제어)

  • 김연희;최종덕;이성범;김종윤;이석준;박찬희;김남균
    • Science of Emotion and Sensibility
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    • v.5 no.4
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    • pp.67-75
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    • 2002
  • The purpose of this study is to assess the ability of balance control in virtual moving surround stimulation using head mount display (HMD) device and force platform in patients with brain injury. Fifteen patients with stroke (mean age 54.47 yrs) and fifteen healthy normal persons participated. COP parameters were obtained total path distance, frequency of anterior-posterior and medial-lateral component by FFT analysis, weight-spectrum analysis in the two different conditions; (1) during comfortable standing with opened or closed eyes, (2) during virtual moving surround stimulation delivered using HMD with four different moving pattern. Moving patterns consisted of close-far, superior-inferior lilting (pitch) , right-left tilting (roll) and horizontal rotation (yaw) movement. In all parameters, the test-retest reliability was high. Also, the construct validity of virtual moving surround stimulation was excellent (p<0.05). A posturographic balance assessment system equiped with virtual moving surround stimulation using HMD is considered clinically useful in evaluation of balance control in patients with brain injury.

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Postural Control in Brain Damage Patients According to Moving Surround (뇌기능 장애 환자의 가상영상(Moving Sorround) 자극에 따른 자세 균형 제어)

  • 김연희;최종덕;이성범;김종윤;이석준;박찬희;김남균
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2002.11a
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    • pp.233-244
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    • 2002
  • The purpose of this study is to assess the ability of balance control in moving surround using head mount device and force platform and to examine the clinical usefulness of COP parameters. Fifteen patients with stroke and healthy persons were participated. COP parameters were obtained as total path distance, frequency of anterior-posterior and medial-lateral component by FFT analysis, weight-spectrum analysis in the two different conditions; (1) in comfortable standing with opened or closed eyes, (2) in virtual moving surround delivered using HMD to four different moving pattern. In virtual moving surround setting, moving pattern was composed of close-far, superior-inferior tilting(pitch), right-left tilting(roll) and horizontal rotation(yaw) movement. In all parameters, the reliebility of COP analysis system was significantly high. Also, the construct validity compared between fifteen patients with stroke and normal persons was excellent in virtual moving surround condition(p

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