507 research outputs found
Student Teaching and Research Laboratory Focusing on Brain-computer Interface Paradigms - A Creative Environment for Computer Science Students -
This paper presents an applied concept of a brain-computer interface (BCI)
student research laboratory (BCI-LAB) at the Life Science Center of TARA,
University of Tsukuba, Japan. Several successful case studies of the student
projects are reviewed together with the BCI Research Award 2014 winner case.
The BCI-LAB design and project-based teaching philosophy is also explained.
Future teaching and research directions summarize the review.Comment: 4 pages, 4 figures, accepted for EMBC 2015, IEEE copyrigh
Novel Virtual Moving Sound-based Spatial Auditory Brain-Computer Interface Paradigm
This paper reports on a study in which a novel virtual moving sound-based
spatial auditory brain-computer interface (BCI) paradigm is developed. Classic
auditory BCIs rely on spatially static stimuli, which are often boring and
difficult to perceive when subjects have non-uniform spatial hearing perception
characteristics. The concept of moving sound proposed and tested in the paper
allows for the creation of a P300 oddball paradigm of necessary target and
non-target auditory stimuli, which are more interesting and easier to
distinguish. We present a report of our study of seven healthy subjects, which
proves the concept of moving sound stimuli usability for a novel BCI. We
compare online BCI classification results in static and moving sound paradigms
yielding similar accuracy results. The subject preference reports suggest that
the proposed moving sound protocol is more comfortable and easier to
discriminate with the online BCI.Comment: 4 pages (in conference proceedings original version); 6 figures,
accepted at 6th International IEEE EMBS Conference on Neural Engineering,
November 6-8, 2013, Sheraton San Diego Hotel & Marina, San Diego, CA; paper
ID 465; to be available at IEEE Xplore; IEEE Copyright 201
Valuation and Hedging of Contracts with Funding Costs and Collateralization
The research presented in this work is motivated by recent papers by Brigo et
al. (2011), Burgard and Kjaer (2009), Cr\'epey (2012), Fujii and Takahashi
(2010), Piterbarg (2010) and Pallavicini et al. (2012). Our goal is to provide
a sound theoretical underpinning for some results presented in these papers by
developing a unified framework for the non-linear approach to hedging and
pricing of OTC financial contracts. We introduce a systematic approach to
valuation and hedging in nonlinear markets, that is, in markets where cash
flows of the financial contracts may depend on the hedging strategies. Our
systematic approach allows to identify primary sources of and quantify various
adjustment to valuation and hedging, primarily the funding and liquidity
adjustment and credit risk adjustment. We propose a way to define no-arbitrage
in such nonlinear markets, and we provide conditions that imply absence of
arbitrage in some specific market trading models. Accordingly, we formulate a
concept of no-arbitrage price, and we provide relevant (non-linear) BSDE that
produces the no-arbitrage price in case when the contract's cash flows can be
replicated
Inter-stimulus Interval Study for the Tactile Point-pressure Brain-computer Interface
The paper presents a study of an inter-stimulus interval (ISI) influence on a
tactile point-pressure stimulus-based brain-computer interface's (tpBCI)
classification accuracy. A novel tactile pressure generating tpBCI stimulator
is also discussed, which is based on a three-by-three pins' matrix prototype.
The six pin-linear patterns are presented to the user's palm during the online
tpBCI experiments in an oddball style paradigm allowing for "the aha-responses"
elucidation, within the event related potential (ERP). A subsequent
classification accuracies' comparison is discussed based on two ISI settings in
an online tpBCI application. A research hypothesis of classification
accuracies' non-significant differences with various ISIs is confirmed based on
the two settings of 120 ms and 300 ms, as well as with various numbers of ERP
response averaging scenarios.Comment: 4 pages, 5 figures, accepted for EMBC 2015, IEEE copyrigh
Head-related Impulse Response Cues for Spatial Auditory Brain-computer Interface
This study provides a comprehensive test of a head-related impulse response
(HRIR) cues for a spatial auditory brain-computer interface (saBCI) speller
paradigm. We present a comparison with the conventional virtual sound
headphone-based spatial auditory modality. We propose and optimize the three
types of sound spatialization settings using a variable elevation in order to
evaluate the HRIR efficacy for the saBCI. Three experienced and seven naive BCI
users participated in the three experimental setups based on ten presented
Japanese syllables. The obtained EEG auditory evoked potentials (AEP) resulted
with encouragingly good and stable P300 responses in online BCI experiments.
Our case study indicated that users could perceive elevation in the saBCI
experiments generated using the HRIR measured from a general head model. The
saBCI accuracy and information transfer rate (ITR) scores have been improved
comparing to the classical horizontal plane-based virtual spatial sound
reproduction modality, as far as the healthy users in the current pilot study
are concerned.Comment: 4 pages, 4 figures, accepted for EMBC 2015, IEEE copyrigh
Chromatic and High-frequency cVEP-based BCI Paradigm
We present results of an approach to a code-modulated visual evoked potential
(cVEP) based brain-computer interface (BCI) paradigm using four high-frequency
flashing stimuli. To generate higher frequency stimulation compared to the
state-of-the-art cVEP-based BCIs, we propose to use the light-emitting diodes
(LEDs) driven from a small micro-controller board hardware generator designed
by our team. The high-frequency and green-blue chromatic flashing stimuli are
used in the study in order to minimize a danger of a photosensitive epilepsy
(PSE). We compare the the green-blue chromatic cVEP-based BCI accuracies with
the conventional white-black flicker based interface.Comment: 4 pages, 4 figures, accepted for EMBC 2015, IEEE copyrigh
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