• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.384-389
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• 2009

In general, gestures can be utilized in human-computer interaction area. Even though the acceleration information is most widely used for the detection of user’s intention, it is hard to use the information under the condition of zero or small variations of gesture velocity due to the inherent characteristics of the accelerometer. In this paper, a natural interaction method which does not require excessive gesture acceleration will be described. Taking advantages of the gravity, the system can generate various types of signals. Also, many problems such as initialization and draft error can be solved using restorative uprighting force of the system.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.548-551
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• 2005

In this paper, three axial accelerometer was used to develop a small sensor module, which was attached to human body to calculate the acceleration in gravity direction by human motion, when it was positioned in any direction. To measure its wearer's walking or running motion using the sensor module, the acquired sensor data was pre-processed to enable its quantitative analysis. The acquired digital data was transformed to orthogonal coordinate value in three dimension and calculated to be single scalar acceleration data in gravity direction and normalized to be physical unit value.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.01a
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• pp.63-65
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• 2013

본 논문에서는 가속도센서와 자이로센서를 통해 측정된 값을 무선 통신을 이용하여 스마트폰으로 전달하여 실시간으로 모션을 분석하는 스마트폰 실시간 모션 분석 알고리즘을 제안한다. 3축 가속도 센서의 실시간 모션 분석과 중력가속도를 사용한 모션 분석의 경우에는 장소나 높이 또는 주변의 자력에 따라 정확한 값을 획득하여 분석하기 어려운 점이 있다. 이에 본 논문에서는 가속도 센서와 자이로 센서를 통하여 보다 정밀한 모션 분석을 하였으며, 이를 이용하여 모션을 실시간으로 분석하여 활용하면 스포츠와 의학 등 다양한 분야에서 활용할 수 있을 것이다.

• Journal of the Korea Computer Graphics Society
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• v.19 no.4
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• pp.13-22
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• 2013

A motion capture system is widely used in movies, computer game, and computer animation industries because it allows for creating realistic human motions efficiently. The inertial motion capture system has several advantages over more popular vision-based systems in terms of the required space and cost. However, it suffers from low accuracy due to the relatively high noise levels of the inertial sensors. In particular, the accelerometer used for measuring gravity direction loses the accuracy when the sensor is moving with non-zero linear acceleration. In this paper, we propose a method to remove the linear acceleration component from the accelerometer data in order to improve the accuracy of measuring gravity direction. In addition, we develop a simple method to calibrate the joint axis of a link to which an inertial sensor belongs as well as the position of a sensor with respect to the link. The calibration enables attaching inertial sensors in an arbitrary position and orientation with respect to a link.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.12
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• pp.1395-1401
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• 2014

In an effort to develop and implement an inertial balance with high performance, the response characteristics of a load cell, which are some of the critical parameters for optimal system design, were evaluated using a sample object of approximately 100 g under microgravity conditions. To this end, a 15-m drop-tower was used to produce microgravity conditions, and the response characteristics of the load cell were investigated in terms of the variations in the magnitude of the deceleration of the sample object, noting that the mass of a living animal should be determined in microgravity. An analysis of the ratio of the inertial forces clearly demonstrated that the average velocity of a load cell plate should be higher than 0.5 m/s to meet the design requirements.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.4
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• pp.30-36
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• 2011

Inertial navigation systems requires gravity model to compute gravity acceleration and its trajectory accuracy depends on the gravity model accuracy especially for a long range flight. The gravity model accuracy is important for satellite orbit prediction as well. The precision gravity model requires a precision coordinate transformation between inertial and Earth fixed coordinates. Precision gravity acceleration algorithms with a coordinate transform are studied and a computer program is developed. The effects of individual model components on trajectory error are analyzed.

• Korean Journal of Optics and Photonics
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• v.15 no.1
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• pp.68-73
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• 2004

Flexure measurement of ring laser gyro was investigated by using an interferometer. A two-beam interferometer of Fiezo-fringe pattern obtained the flexure angle in 1-gravity acceleration and the higher acceleration environments. These environments were made with the addition of dummy mass to the ring laser gyro axis. The flexure angle change for 1-gravity acceleration change was measured as 2.37 arcsec/g with low repeatability error of 0.01 arcsec/g. The laser navigation system consisting of 3 flexure-reduced ring laser gyros showed the improvement of flexure error.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.01a
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• pp.59-60
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• 2012

자유 낙하하는 물체가 받는 힘은 중력 뿐이다. 우리는 중력만을 받아서 운동하는 것을 자유 낙하 운동이라고 하고 자유 낙하하는 물체를 자유낙체라 한다. 다시 말해서, 물체의 초기 운동 상태와 무관하게 중력의 영향으로만 자유롭게 낙하하는 물체를 말하는 것이다. 본 논문에서는 공기의 저항을 무시하고, 수직방향으로 짧은 거리의 범위 내에서 고도에 의한 자유낙하 가속도의 변화가 없다는 가정을 하고, 자동차가 수직 상 방향으로 출발하여 도약하고 최고점에 도달하는 시간, 최대높이, 자동차가 출발 위치로 돌아오는 시간과 자동차의 속도, 자동차가 땅에 떨어질 때의 시간 및 속도에 대해 알 수 있다.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.3
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• pp.216-220
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• 2009

In this paper we propose a motion recognition method for handheld controller 3-D acceleration signals, generated by 3 axis accelerometer in the controller, are transmitted to the computer by Bluetooth communication. We extract motion segments from continuous acceleration signals and apply to each motion model, which is trained in training phase. Hidden Markov Model was used to model each motion. We applied proposed method to three motion sets, the recognition result was good enough to practical use.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.221-228
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• 2014

In this paper, the operational concept and the navigation algorithms for the gliding guided artillery munition are studied. The gliding guided artillery munition has wings for gliding; therefore spin of the munition should be eliminated. The previous navigation algorithms assumed a spinning munition with constant angular velocity; hence, they cannot be applied for the gliding munition. Moreover, lateral stability becomes worse due to decrease of angular momentum. Therefore, side force should be controlled to improve the stability, and the munition should maneuver, then the previous navigation algorithms for typical fixed-wing aircraft cannot be applied. In this paper, we apply the previous navigation algorithms for the spinning munition. Spin is eliminated and wings are deployed based on the estimation results, and the advanced navigation algorithm for the non-spinning munition is introduced.