• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.8
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• pp.1901-1906
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• 2010

This classification of walking patterns is important and many kinds of applications. Therefore, we attempted to classify walking on level ground from slow walking to fast walking using a waist acceleration signal. A tri-axial accelerometer was fixed to the subject's waist and the three acceleration signals were recorded by bluetooth module at a sampling rate of 100 Hz eleven healthy. The data were analyzed using discrete wavelet transform. Walking patterns were classified using two parameters; One was the ratio between the power of wavelet coefficients which were corresponded to locomotion and total power in the anteroposterior direction (RPA). The other was the ratio between root mean square of wavelet coefficients at the anteroposterior direction and that at the vertical direction(RAV). Slow walking could be distinguished by the smallest value in RPA from other walking pattern. Fast walking could be discriminated from level walking using RAV. It was possible to classify the walking pattern using acceleration signal in healthy people.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.342-349
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• 2015

The objective of this study was to compare the unimanual and bimanual complementary movements of the affected upper extremity. Thirty participants living in Busan area with post-stroke hemiparesis were involved in this study. They were selected according to twelve criteria. We used the Fitmeter accelerometer to measure Signal Vector Magnitude, peak acceleration and peak deceleration. The movement time and Signal Vector Magnitude of bimanual complementary movement were less than those of unimanual movement(p<0.05). Therefore, we suggest that bimanual complementary movement is more useful, as for the kinematic aspect, than unimanual movement when a person with stroke perform activities of daily living.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.331-338
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• 2004

In this paper, stiffness and damping matrices are experimentally constructed using structural modal information on frequencies, damping ratios and modal vectors, which are obtained by shaking table tests. The acceleration of the shaking table is used as the input signal, and the resulting acceleration of each floor is measured as output signal. The characteristic and limitation of modal information from shaking table test are obtained by Common Based-normalized System Identification(CBSI) technique which is based on time domain information.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1033-1034
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• 2009

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.5
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• pp.562-572
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• 1992

In this paper, we propose software algorithms which provide acceleration/deceleration characteristics essential to high dynamic performance at the transient states where industrial robots or CNC machine tools start and stop. Software acceleration/deceleration methods are derived from the mathematical analyses of typical hardware systems controlling acceleration/deceleration. These methods make servo motors, which drive axes of motion, start and stop smoothly without vibration in the repeated tools. The path error, which is one of the most significant factors in the performance evaluation of industrial robots or CNC machine tools, is analyzed for linear, exponential, and parabolic acceleration/deceleration algorithms in case of circular interpolation. The analyses show that path error consists of the distance between the required path and generated one through acceleration/deceleration, and that between the generated one through acceleration/deceleration algorithm and the actual one of the end effector of the industrial robot or tool of the CNC equipment.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1968-1970
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• 2003

In this paper we propose a system to forecast the dangerous behavior of the dementia patients. Basic idea of our approach is to measure the body movements of the dementia patients using the acceleration sensor. Based on the data measured, warning the care-givers about possible dangerous actions like falling down from the bed and slipping down onto the floor to some extent. The signals measured by the acceleration sensor are processed by a one-chip computer. Based on the diagnosis of the one-chip computer , alert signal is generated to the care-giver by a wire-less signal. The sensor is implemented in a compact body . Applicability of the system is now being examined at a nursing home.

• Smart Media Journal
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• v.6 no.3
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• pp.83-88
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• 2017

The data analysis system using Big-data is worthy to be used in various fields such as politics, traffic, natural disaster, shopping, customer management, medical care, and weather information. Particularly, the analysis of the momentum of an individual using an acceleration signal collected from a wearable device has already been widely used. However, since the data used in such a system stores only the data necessary for measuring the individual activity, it does not provide various analysis results other than the exercise amount of the individual. In this paper, I propose a system that analyzes collective behavior pattern and activity based on the acceleration signal that can be collected from personal smartphones for 24 hours a day and stored in big data. I also propose a system that sends acceleration signals and receives analysis results using standard messaging to use on various smart devices.

• The Journal of the Acoustical Society of Korea
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• v.42 no.3
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• pp.214-220
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• 2023

In this paper, we propose a method to improve texture recognition performance from haptic acceleration signals representing the texture characteristics of object surface materials by using a Conformer model that combines the advantages of a convolutional neural network and a transformer. In the proposed method, three-axis acceleration signals generated by impact sound and vibration are combined into one-dimensional acceleration data while a person contacts the surface of the object materials using a tool such as a stylus , and the logarithmic Mel-spectrogram is extracted from the haptic acceleration signal similar to the audio signal. Then, Conformer is applied to the extracted the logarithmic Mel-spectrogram to learn main local and global frequency features in recognizing the texture of various object materials. Experiments on the Lehrstuhl für Medientechnik (LMT) haptic texture dataset consisting of 60 materials to evaluate the performance of the proposed model showed that the proposed method can effectively recognize the texture of the object surface material better than the existing methods.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.477-482
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• 2002

This research is concerned with the study of an active vibration absorber using piezoelectric actuators and Isolation pad. The active isolation system consists of 4-pairs of PZT actuators bonded on the surface of an aluminum plate and a passive damping material. The active system is connected to the passive system in series. The Signals of the accelerometers are fed into the PZT actuator through the controller. We proposed a new control technique which can deal with the shock as well as the base excitation in this study. The Positive Acceleration Feedback(PAE) tuned to the natural frequency of the vibration isolation system is used to suppress the vibrations caused by the shock using the top accelerometer signal. The Negative Acceleration Feedback (NAF) based on the base acceleration signal is used to counteract the base motion. Experimental results show that the proposed active vibration isolation system can suppress vibrations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.28-31
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• 2014

This paper is concerned with the active vibration control of washing machine. To this end, a new control algorithm utilizing an acceleration signal as a sensor signal is newly developed based on the principle of a dynamic absorber. The resulting control algorithm was implemented digitally on the DSP board. The accelerometer and the active linear actuator were used as sensor and actuator for the active vibration control of washing machine. Experimental results show that the proposed control algorithm can be effectively used for a controller which uses an accelerometer.