4 research outputs found
On Some DOA Algorithms for Tri-axial Geophone
In this paper a short study of some basic methods of DOA of a seismic wave using so called tri-axial geophone has been presented. The proposed methods exploit the properties of Rayleigh surface plane wave to find DOA of an incoming seismic wave using inner products of appropriately filtered signals recorded by geophones. The advantage of the proposed method is its simplicity and ease of implementation in small DSP or application processors still retaining pretty good accuracy. A number of example results for real data have been given
Multi-sensor based ambient assisted living system
Ankara : The Department of Electrical and Electronics Engineering and the Graduate School of Engineering and Science of Bilkent University, 2013.Thesis (Master's) -- Bilkent University, 2013.Includes bibliographical references leaves 76-84.An important goal of Ambient Assisted Living (AAL) research is to contribute
to the quality of life of the elderly and handicapped people and help them to
maintain an independent lifestyle with the use of sensors, signal processing and
the available telecommunications infrastructure. From this perspective, detection
of unusual human activities such as falling person detection has practical applications.
In this thesis, a low-cost AAL system using vibration and passive infrared
(PIR) sensors is proposed for falling person detection, human footstep detection,
human motion detection, unusual inactivity detection, and indoor flooding
detection applications. For the vibration sensor signal processing, various frequency
analysis methods which consist of the discrete Fourier transform (DFT),
mel-frequency cepstral coefficients (MFCC), discrete wavelet transform (DWT)
with different filter-banks, dual-tree complex wavelet transform (DT-CWT), and
single-tree complex wavelet transform (ST-CWT) are compared to each other to
obtain the best possible classification result in our dataset. Adaptive-threshold
based Markov model (MM) classifier is preferred for the human footstep detection.
Vibration sensor based falling person detection system employs Euclidean
distance and support vector machine (SVM) classifiers and these classifiers are
compared to each other. PIR sensors are also used for falling person detection
and this system employs two PIR sensors. To achieve the most reliable system, a
multi-sensor based falling person detection system which employs one vibration
and two PIR sensors is developed. PIR sensor based system has also the capability
of detecting uncontrolled flames and this system is integrated to the overall
system. The proposed AAL system works in real-time on a standard personal
computer or chipKIT Uno32 microprocessors without computers. A network is
setup for the communication of the Uno32 boards which are connected to different
sensors. The main processor gives final decisions and emergency alarms
are transmitted to outside of the smart home using the auto-dial alarm system via telephone lines. The resulting AAL system is a low-cost and privacy-friendly
system thanks to the types of sensors used.Yazar, AhmetM.S