929 research outputs found
Measuring Performance of Virtual Keyboards Based on Cyclic Scanning
This paper presents an exhaustive study into the
different topologies of virtual ambiguous keyboards that
operate by scanning techniques, analyzing the text entry
average time (tc) and the average number of user inputs
(UIc) per character.
An mathematical model shows that in comparison with
unambiguous one, text entry, in multi-tap mode, doesn’t
offers better performance,because both tc and UIc are
greater in them. Another method of text entry, called Tnk
(Text in n keys), offers improvement with respect to
unambiguous keyboards. But solely highly ambiguous keyboard
(4-keys keyboards) shows a jointly reduction in tc and
UIc . Results obtained with the model do to focus on highly
ambiguous keyboard. This paper demonstrate, using
simulation with extensive text, that character prediction with
TnK mode only have better performance than unambiguous
keyboard with character prediction in UIc parameter.
Another techniques of text entry are also studied.Junta de Andalucía p08-TIC-363
An Ambiguous Technique for Nonvisual Text Entry
Text entry is a common daily task for many people, but it can be a challenge for people with visual impairments when using virtual touchscreen keyboards that lack physical key boundaries. In this thesis, we investigate using a small number of gestures to select from groups of characters to remove most or all dependence on touch locations. We leverage a predictive language model to select the most likely characters from the selected groups once a user completes each word.
Using a preliminary interface with six groups of characters based on a Qwerty keyboard, we find that users are able to enter text with no visual feedback at 19.1 words per minute (WPM) with a 2.1% character error rate (CER) after five hours of practice. We explore ways to optimize the ambiguous groups to reduce the number of disambiguation errors. We develop a novel interface named FlexType with four character groups instead of six in order to remove all remaining location dependence and enable one-handed input. We compare optimized groups with and without constraining the group assignments to alphabetical order in a user study. We find that users enter text with no visual feedback at 12.0 WPM with a 2.0% CER using the constrained groups after four hours of practice. There was no significant difference from the unconstrained groups.
We improve FlexType based on user feedback and tune the recognition algorithm parameters based on the study data. We conduct an interview study with 12 blind users to assess the challenges they encounter while entering text and solicit feedback on FlexType, and we further incorporate this feedback into the interface. We evaluate the improved interface in a longitudinal study with 12 blind participants. On average, participants entered text at 8.2 words per minute using FlexType, 7.5 words per minute using a Qwerty keyboard with VoiceOver, and at 26.9 words per minute using Braille Screen Input
A new multisensor software architecture for movement detection: Preliminary study with people with cerebral palsy
A five-layered software architecture translating movements into mouse clicks has been developed and tested on an
Arduino platform with two different sensors: accelerometer and flex sensor. The archi-tecture comprises low-pass
and derivative filters, an unsupervised classifier that adapts continuously to the strength of the user's movements and
a finite state machine which sets up a timer to prevent in-voluntary movements from triggering false positives.
Four people without disabilities and four people with cerebral palsy (CP) took part in the experi-ments. People
without disabilities obtained an average of 100% and 99.3% in precision and true positive rate (TPR) respectively and
there were no statistically significant differences among type of sensors and placement. In the same experiment,
people with disabilities obtained 97.9% and 100% in precision and TPR respectively. However, these results worsened
when subjects used the system to access a commu-nication board, 89.6% and 94.8% respectively. With their usual
method of access-an adapted switch- they obtained a precision and TPR of 86.7% and 97.8% respectively. For 3-outof-
4 participants with disabilities our system detected the movement faster than the switch.
For subjects with CP, the accelerometer was the easiest to use because it is more sensitive to gross motor motion
than the flex sensor which requires more complex movements. A final survey showed that 3-out-of-4 participants
with disabilities would prefer to use this new technology instead of their tra-ditional method of access
Technical Workshop: Advanced Helicopter Cockpit Design
Information processing demands on both civilian and military aircrews have increased enormously as rotorcraft have come to be used for adverse weather, day/night, and remote area missions. Applied psychology, engineering, or operational research for future helicopter cockpit design criteria were identified. Three areas were addressed: (1) operational requirements, (2) advanced avionics, and (3) man-system integration
Frankenstein: Advanced Wireless Fuzzing to Exploit New Bluetooth Escalation Targets
Wireless communication standards and implementations have a troubled history
regarding security. Since most implementations and firmwares are closed-source,
fuzzing remains one of the main methods to uncover Remote Code Execution (RCE)
vulnerabilities in deployed systems. Generic over-the-air fuzzing suffers from
several shortcomings, such as constrained speed, limited repeatability, and
restricted ability to debug. In this paper, we present Frankenstein, a fuzzing
framework based on advanced firmware emulation, which addresses these
shortcomings. Frankenstein brings firmware dumps "back to life", and provides
fuzzed input to the chip's virtual modem. The speed-up of our new fuzzing
method is sufficient to maintain interoperability with the attached operating
system, hence triggering realistic full-stack behavior. We demonstrate the
potential of Frankenstein by finding three zero-click vulnerabilities in the
Broadcom and Cypress Bluetooth stack, which is used in most Apple devices, many
Samsung smartphones, the Raspberry Pis, and many others.
Given RCE on a Bluetooth chip, attackers may escalate their privileges beyond
the chip's boundary. We uncover a Wi-Fi/Bluetooth coexistence issue that
crashes multiple operating system kernels and a design flaw in the Bluetooth
5.2 specification that allows link key extraction from the host. Turning off
Bluetooth will not fully disable the chip, making it hard to defend against RCE
attacks. Moreover, when testing our chip-based vulnerabilities on those
devices, we find BlueFrag, a chip-independent Android RCE.Comment: To be published at USENIX Securit
Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 192
This bibliography lists 247 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1979
Index to 1986 NASA Tech Briefs, volume 11, numbers 1-4
Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1986 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences
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