5,021 research outputs found
A layered fuzzy logic controller for nonholonomic car-like robot
A system for real time navigation of a nonholonomic car-like robot in a dynamic environment consists of two layers is described: a Sugeno-type fuzzy motion planner; and a modified proportional navigation based fuzzy controller. The system philosophy is inspired by human routing when moving between obstacles based on visual information including right and left views to identify the next step to the goal. A Sugeno-type fuzzy motion planner of four inputs one output is introduced to give a clear direction to the robot controller. The second stage is a modified proportional navigation based fuzzy controller based on the proportional navigation guidance law and able to optimize the robot's behavior in real time, i.e. to avoid stationary and moving obstacles in its local environment obeying kinematics constraints. The system has an intelligent combination of two behaviors to cope with obstacle avoidance as well as approaching a target using a proportional navigation path. The system was simulated and tested on different environments with various obstacle distributions. The simulation reveals that the system gives good results for various simple environments
The Velocity of the Propagating Wave for General Coupled Scalar Systems
We consider spatially coupled systems governed by a set of scalar density
evolution equations. Such equations track the behavior of message-passing
algorithms used, for example, in coding, sparse sensing, or
constraint-satisfaction problems. Assuming that the "profile" describing the
average state of the algorithm exhibits a solitonic wave-like behavior after
initial transient iterations, we derive a formula for the propagation velocity
of the wave. We illustrate the formula with two applications, namely
Generalized LDPC codes and compressive sensing.Comment: 5 pages, 5 figures, submitted to the Information Theory Workshop
(ITW) 2016 in Cambridge, U
Packaging of RF Mems Switching Functions on Alumina Substrate
Recently the strong demands in wireless communication requires expanding
development for the application of RF MEMS (Radio Frequency micro electro
mechanical systems) sensing devices such as micro-switches, tunable capacitors
because it offers lower power consumption, lower losses, higher linearity and
higher Q factors compared with conventional communications components. To
accelerate commercialisation of RF MEMS products, development for packaging
technologies is one of the most critical issues should be solved beforehand.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Cabbage and vitamin E: their effect on colon tumor formation in mice.
The effects of cabbage and vitamin E on colon carcinogenesis were
investigated in Swiss mice treated with 1,2-dimethylhydrazine. Throughout
the experiment the mice were fed a laboratory chow diet (46 mg vitamin E
per kg) or chow containing 13 g cabbage per 100 g or 180 mg vitamin E
per kg. Starting after 31 days of diet treatment the mice received 7 weekly
s.c. injections of DMH. They were sacrificed 17 weeks after the first dose
of DMH. While diet did not significantly alter colon tumor response, some
trends were observed. Female mice given cabbage had a higher incidence.
(percent of mice with a tumor) and multiplicity (tumors per tumor bearing
mouse) of colon tumors. Males were little affected by cabbage apart from
a lower incidence of adenocarcinomas. Compared with mice fed the control
diet those given vitamin E had a higher colon tumor incidence, This effect,
which was stronger in females, was due to an increased incidence of
adenomas. Vitamin E had little apparent affect on tumor multiplicity apart
from a reduction in adenocarcinomas in females and adenomas in males.
The data do not support the view that cabbage and vitamin E are protective
against colon cancer
Changes in pH and levels of B-glucosidase, B-glucuronidase and reducing activity as food residue passes along the mouse colon
The contents were collected from successive regions of the colon of Swiss mice.
Ana(vses show that the pH rises by about 0.55 pH units between the cecum and the
distal colon. The level of p-glucuronidase falls sharply, typically 2 to 3 fold;, as food
residue leaves the cecum. This is followed by a large rise in the distal c%n, mvund
1.6 to 4 fold, about half of 1vhich is due to the concentrating ejlect caused by loss
of water. lvleasurements were also made of nonspecific reducing activity, the level
of which rises by about 74% along the colon mainly because of water loss. For each
of the above parameters similar results were observed using old and young mice and
with diets high and low in fat. Studies indicated that the reducing activity is
nonenzymic
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