3,754 research outputs found
On quasi-Pr\"{u}fer and UM domains
In this note we show that an integral domain of finite -dimension is a
quasi-Pr\"{u}fer domain if and only if each overring of is a -Jaffard
domain. Similar characterizations of quasi-Pr\"{u}fer domains are given by
replacing -Jaffard domain by -stably strong S-domain, and -strong
S-domain. We also give new characterizations of UM domains.Comment: 6 Page
Activity Recognition using Hierarchical Hidden Markov Models on Streaming Sensor Data
Activity recognition from sensor data deals with various challenges, such as
overlapping activities, activity labeling, and activity detection. Although
each challenge in the field of recognition has great importance, the most
important one refers to online activity recognition. The present study tries to
use online hierarchical hidden Markov model to detect an activity on the stream
of sensor data which can predict the activity in the environment with any
sensor event. The activity recognition samples were labeled by the statistical
features such as the duration of activity. The results of our proposed method
test on two different datasets of smart homes in the real world showed that one
dataset has improved 4% and reached (59%) while the results reached 64.6% for
the other data by using the best methods
Natural melting within a spherical shell
Fundamental heat transfer experiments were performed on the melting of a phase change medium in a spherical shell. Free expansion of the medium into a void space within the sphere was permitted. A step function temperature jump on the outer shell wall was imposed and the timewise evolution of the melting process and the position of the solid-liquid interface was photographically recorded. Numerical integration of the interface position data yielded information about the melted mass and the energy of melting. It was found that the rate of melting and the heat transfer were significantly affected by the movement of the solid medium to the base of the sphere due to gravity. The energy transfer associated with melting was substantially higher than that predicted by the conduction model. Furthermore, the radio of the measured values of sensible energy in the liquid melt to the energy of melting were nearly proportional to the Stefan number. The experimental results are in agreement with a theory set forth in an earlier paper
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