7,870 research outputs found
Iris segmentation
The quality of eye image data become degraded particularly when the image is taken in the non-cooperative acquisition environment such as under visible wavelength illumination. Consequently, this environmental condition may lead to noisy eye images, incorrect localization of limbic and pupillary boundaries and eventually degrade the performance of iris recognition system. Hence, this study has compared several segmentation methods to address the abovementioned issues. The results show that Circular Hough transform method is the best segmentation method with the best overall accuracy, error rate and decidability index that more tolerant to ânoiseâ such as reflection
Overview of sensors suitable for active flow control methods
HlavnĂœm cieÄŸom tejto bakalĂĄrskej prĂĄce bolo vytvorenie prehÄŸadu vyvĂjanĂœch a uĆŸ aplikovanĂœch senzorov pre ĂșÄely aktĂvneho riadenia prĂșdov. Senzory musia splĆovaĆ„ niektorĂ© podmienky, preto vĂœber senzorov bol naviazanĂœ na reĂĄlnych vĂœsledkoch testovacĂch programov, popis ktorĂœch tvorĂ prvĂș ÄasĆ„ tejto bakalĂĄrskej prĂĄce. Opis technolĂłgie a princĂp fungovania senzorov je popĂsanĂœ v druhej Äasti tejto prĂĄce.The main purpose of this bachelor thesis was to create the overview of the sensors developed for the future active flow control applications and overview the sensors already used in the active flow control applications. The sensors have to fulfil several requirements, so selection for the overview was based on the real flight test programs results, which were described in the first part of the thesis. The sensors technology description and operation principles were included in the second part of the thesis
Wireless Intraocular Pressure Sensing Using Microfabricated Minimally Invasive Flexible-Coiled LC Sensor Implant
This paper presents an implant-based wireless pressure
sensing paradigm for long-range continuous intraocular
pressure (IOP) monitoring of glaucoma patients. An implantable
parylene-based pressure sensor has been developed, featuring an
electrical LC-tank resonant circuit for passive wireless sensing
without power consumption on the implanted site. The sensor
is microfabricated with the use of parylene C (poly-chlorop-
xylylene) to create a flexible coil substrate that can be folded
for smaller physical form factor so as to achieve minimally invasive
implantation, while stretched back without damage for
enhanced inductive sensorâreader coil coupling so as to achieve
strong sensing signal. A data-processed external readout method
has also been developed to support pressure measurements. By
incorporating the LC sensor and the readout method, wireless
pressure sensing with 1-mmHg resolution in longer than 2-cm distance
is successfully demonstrated. Other than extensive on-bench
characterization, device testing through six-month chronic in vivo
and acute ex vivo animal studies has verified the feasibility and
efficacy of the sensor implant in the surgical aspect, including
robust fixation and long-term biocompatibility in the intraocular
environment. With meeting specifications of practical wireless
pressure sensing and further reader development, this sensing
methodology is promising for continuous, convenient, direct, and
faithful IOP monitoring
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