15,511 research outputs found
High Accuracy Human Activity Monitoring using Neural network
This paper presents the designing of a neural network for the classification
of Human activity. A Triaxial accelerometer sensor, housed in a chest worn
sensor unit, has been used for capturing the acceleration of the movements
associated. All the three axis acceleration data were collected at a base
station PC via a CC2420 2.4GHz ISM band radio (zigbee wireless compliant),
processed and classified using MATLAB. A neural network approach for
classification was used with an eye on theoretical and empirical facts. The
work shows a detailed description of the designing steps for the classification
of human body acceleration data. A 4-layer back propagation neural network,
with Levenberg-marquardt algorithm for training, showed best performance among
the other neural network training algorithms.Comment: 6 pages, 4 figures, 4 Tables, International Conference on Convergence
Information Technology, pp. 430-435, 2008 Third International Conference on
Convergence and Hybrid Information Technology, 200
Frequency based Classification of Activities using Accelerometer Data
This work presents, the classification of user activities such as Rest, Walk
and Run, on the basis of frequency component present in the acceleration data
in a wireless sensor network environment. As the frequencies of the above
mentioned activities differ slightly for different person, so it gives a more
accurate result. The algorithm uses just one parameter i.e. the frequency of
the body acceleration data of the three axes for classifying the activities in
a set of data. The algorithm includes a normalization step and hence there is
no need to set a different value of threshold value for magnitude for different
test person. The classification is automatic and done on a block by block
basis.Comment: IEEE International Conference on Multisensor Fusion and Integration
for Intelligent Systems, 2008. MFI 200
Recommended from our members
Orthopedic Surgery Planning Based on the Integration of Reverse Engineering and Rapid Prototyping
This paper describes orthopedic surgical planning based on the integration of RE and RP.
Using symmetrical characteristics of the human body, CAD data of the original bone without
damages for the injured extent are generated from a mirror transformation of undamaged bone
data for the uninjured extent. The physical model before the injury is manufactured from RP
apparatus. Surgical planning, such as the selection of the proper implant, pre-forming of the
implant, decision of fixation positions and incision sizes, etc., is determined by a physical
simulation using the physical model. In order to examine the applicability and efficiency of
surgical planning technology for orthopedics, various case studies, such as a proximal tibia
plateau fracture, a distal tibia comminuted fracture and an iliac wing fracture of pelvis, are
carried out. As a result of the examination, it has been shown that the orthopedic surgical
planning based on the integration of RE and RP is an efficient surgical tool.Mechanical Engineerin
Synergistic multi-doping effects on the Li7La3Zr2O12 solid electrolyte for fast lithium ion conduction.
Here, we investigate the doping effects on the lithium ion transport behavior in garnet Li7La3Zr2O12 (LLZO) from the combined experimental and theoretical approach. The concentration of Li ion vacancy generated by the inclusion of aliovalent dopants such as Al(3+) plays a key role in stabilizing the cubic LLZO. However, it is found that the site preference of Al in 24d position hinders the three dimensionally connected Li ion movement when heavily doped according to the structural refinement and the DFT calculations. In this report, we demonstrate that the multi-doping using additional Ta dopants into the Al-doped LLZO shifts the most energetically favorable sites of Al in the crystal structure from 24d to 96 h Li site, thereby providing more open space for Li ion transport. As a result of these synergistic effects, the multi-doped LLZO shows about three times higher ionic conductivity of 6.14 × 10(-4) S cm(-1) than that of the singly-doped LLZO with a much less efforts in stabilizing cubic phases in the synthetic condition
NMR study on the stability of the magnetic ground state in MnCrO
The canting angles and fluctuation of the magnetic ion spins of spinel oxide
MnCrO were studied by nuclear magnetic resonance (NMR) at low
temperatures, which has a collinear ferrimagnetic order below and a
ferrimagnetic spiral order below . Contrary to previous reports,
only one spin canting angle of Cr ions was observed. The spin canting angles of
Mn and Cr ions in the ferrimagnetic spiral obtained at a liquid-He temperature
were 43\,^{\circ} and 110\,^{\circ}, respectively. The nuclear spin-spin
relaxation was determined by the Suhl-Nakamura interaction at low temperatures
but the relaxation rate increases rapidly as the temperature
approaches . This indicates that the fluctuation of the spiral component
becomes faster as the temperature increases but not fast enough to leave an
averaged hyperfine field to nuclei in the time scale of nuclear spin precession
in the ferrimagnetic phase, which is on the order of s. The spiral
volume fraction measured for various temperatures reveals that the collinear
and the spiral ferrimagnetic phases are mixed below the transition temperature
of the spiral order. The temperature hysteresis in the volume fraction implies
that this transition has first-order characteristics.Comment: 13 pages, 5 figure
- …