A robust hybrid feedback active noise cancellation headset

This paper investigates the robustness of a hybrid analog/digital feedback active noise cancellation (ANC) headset system. The digital ANC systems with the filtered-x least-mean-square (FXLMS) algorithm require accurate estimation of the secondary path for the stability and convergence of the algorithm. This demands a great challenge for the ANC headset design because the secondary path may fluctuate dramatically such as when the user adjusts the position of the ear-cup. In this paper, we analytically show that adding an analog feedback loop into the digital ANC systems can effectively reduce the plant fluctuation, thus achieving a more robust system. The method for designing the analog controller is highlighted. A practical hybrid analog/digital feedback ANC headset has been built and used to conduct experiments, and the experimental results show that the hybrid headset system is more robust under large plant fluctuation, and has achieved satisfactory noise cancellation for both narrowband and broadband noises.

Implementation of robust hybrid feedback FxLMS active noise cancellation headset

Instability is a serious problem for acoustic Active Noise Cancellation (ANC) headsets as a result of large errors in estimating the transfer function of the plant. Typically this occurs when, for example, a wearer adjusts the headset. In this paper, the instability problem of adaptive ANC headset is addressed. To ensure stability of the whole system, we propose a hybrid solution consisting of an analog feedback loop parallel to the digital loop, and the role of the analog loop in stabilizing the headset is analyzed theoretically. Finally the methodology of implementing such a hybrid ANC headset is described in detail. The experiments carried out on the headset prototype show that the headset is robust under considerable fluctuations of the plant transfer characteristics, and has very good noise cancellation performance both for narrow-band and wide-band disturbances.

Improving the performance of GIS/spatial analysts though novel applications of the Emotiv EPOC EEG headset

Geospatial information systems are used to analyze spatial data to provide decision makers with relevant, up-to-date, information. The processing time required for this information is a critical component to response time. Despite advances in algorithms and processing power, we still have many “human-in-the-loop” factors. Given the limited number of geospatial professionals, analysts using their time effectively is very important. The automation and faster humancomputer interactions of common tasks that will not disrupt their workflow or attention is something that is very desirable. The following research describes a novel approach to increase productivity with a wireless, wearable, electroencephalograph (EEG) headset within the geospatial workflow.

Organizational maintenance repair parts and special tools lists for headset-microphone H 182/PT, (NSN 5965-00-069-8885).

Includes index.

Operator, organizational, DS, GS, and depot maintenance manual : headset-microphone H-182/PT.

"4 March 1968."

Direct support and general support maintenance repair parts and special tools lists (including depot maintenance repair parts and special tools) for headset-microphone H-182/PT, (NSN 5965-00-069-8885).

"7 April 1980."

Organizational, direct support, and general support maintenance repair parts and special tools lists (including depot maintenance repair parts and special tools) : headset-microphone H-101A/U, FSN 5965-627-8382.

Includes index.

Operator's, organizational, direct support, general support, and depot maintenance manual including repair parts and special tools list : headset-microphone kit MK-1039/G.

"December 1966."

Gaze angle: a possible mechanism of visual stress in virtual reality headsets

It is known that some Virtual Reality (VR) head-mounted displays (HMDs) can cause temporary deficits in binocular vision. On the other hand, the precise mechanism by which visual stress occurs is unclear. This paper is concerned with a potential source of visual stress that has not been previously considered with regard to VR systems: inappropriate vertical gaze angle. As vertical gaze angle is raised or lowered the 'effort' required of the binocular system also changes. The extent to which changes in vertical gaze angle alter the demands placed upon the vergence eye movement system was explored. The results suggested that visual stress may depend, in part, on vertical gaze angle. The proximity of the display screens within an HMD means that a VR headset should be in the correct vertical location for any individual user. This factor may explain some previous empirical results and has important implications for headset design. Fortuitously, a reasonably simple solution exists.

Moderating effect of ear preference on personality in the prediction of sales performance

This study examined the relationship between ear preference, personality, and performance ratings on 203 telesales staff. Social desirability scores were a significant predictor of two relatively independent sets of supervisor ratings (actual performance and developmental potential) in interaction with ear preference. It was found that the social desirability scale was a significant positive predictor for staff preferring a right ear headset, but a negative predictor for staff preferring a left ear headset. These results were interpreted in terms of different strategies used to achieve successful sales.

JAVA APIS FOR BLUETOOTH WIRELESS TECHNOLOGY

Bluetooth™ Teknologia - Bluetooth Wireless Technology - on lyhyen kantaman langaton kommunikointiteknologia. Vaikka se onkin ensisijaisesti suunniteltu kaapelin korvaajaksi laitteiden omaan toimintaan liittyvässä liikenteessä, voidaan sitä myös käyttää alustana monen käyttäjien peleissä ja muissa vastaavissa sovelluksissa. Tassa diplomityössä esitellään Bluetooth teknologia sovellusohjelmoijan näkökulmasta. Työssä esitellään teollisuuskonsortion määrittelemä Java-ohjelmointirajapinta Bluetooth teknologiaan. Tämän rajapinnan avulla voidaan kehittää kannettavia sovelluksia jotka kommunikoivat Bluetooth yhteyden yli. Rajapinta pohjautuu "Java™ 2 Microedition" alustaan ja on siten toteutettavissa myös pienissä laitteissa kuten matkapuhelimissa. Työssä esitellään lyhyesti rajapinnan keskeiset osat sekä annetaan esimerkki rajapinnan käytöstä. Työn konstruktiivisessa osassa rajapinnan keskeiset on toteutettu kahdelle eri alustalle: Sambian™ ja Microsoft® Windows® käyttöjärjestelmille. Talla tavalla on saatu arvokasta tietoa siitä, miten kyseinen rajapinta tulisi toteuttaa ja myös siitä miten sovellukset sitä käyttäisivät. Keskeiset suunnitteluratkaisut ja saadut kokemukset on raportoitu työn kirjallisessa osassa. Vaikka työn konstruktiivinen osuus onkin luonteeltaan esitutkimus eikä tähdännyt tuotteeseen, on tuloksena syntynyttä rajapintaa tarkoitus käyttää useassa Nokian sisäisessä tutkimus-ja kehityshankkeessa.

Detection of Epilepsy with a Commercial EEG Headband

Epilepsy is a chronic brain disorder, characterized by reoccurring seizures. Automatic sei-zure detector, incorporated into a mobile closed-loop system, can improve the quality of life for the people with epilepsy. Commercial EEG headbands, such as Emotiv Epoc, have a potential to be used as the data acquisition devices for such a system. In order to estimate that potential, epileptic EEG signals from the commercial devices were emulated in this work based on the EEG data from a clinical dataset. The emulated characteristics include the referencing scheme, the set of electrodes used, the sampling rate, the sample resolution and the noise level. Performance of the existing algorithm for detection of epileptic seizures, developed in the context of clinical data, has been evaluated on the emulated commercial data. The results show, that after the transformation of the data towards the characteristics of Emotiv Epoc, the detection capabilities of the algorithm are mostly preserved. The ranges of acceptable changes in the signal parameters are also estimated.

Environnement virtuel générateur d’émotions

Les émotions jouent un rôle important dans la prise de décision quotidienne. En effet, elles influencent grandement la manière dont les individus interagissent avec leur environnement. Dans cette étude nous avons premièrement conçu un environnement virtuel de conduite automobile, puis créé des scénarios générateurs d’émotions à l’aide de la méthode Belief-Desire-Intention. Nous avons évalué l’efficacité de ces scénarios à l’aide d’un groupe de 30 personnes et d’un casque électroencéphalogramme pour mesurer leurs émotions. On observe que plus de 70% des scénarios conçus avec cette méthode ont généré l’émotion que l’on avait anticipée chez 52% à 76% des participants. La deuxième phase de cette expérience porte sur la réduction d’émotions avec un agent correcteur. Nous avons noté une efficacité de la réduction des émotions allant de 36.4% jusqu’à 70.0% des participants à travers les différents scénarios.

Performance analysis of the unconstrained FxLMS algorithm for active noise control

The paper analyzes the performance of the unconstrained filtered-x LMS (FxLMS) algorithm for active noise control (ANC), where we remove the constraints on the controller that it must be causal and has finite impulse response. It is shown that the unconstrained FxLMS algorithm always converges to, if stable, the true optimum filter, even if the estimation of the secondary path is not perfect, and its final mean square error is independent of the secondary path. Moreover, we show that the sufficient and necessary stability condition for the feedforward unconstrained FxLMS is that the maximum phase error of the secondary path estimation must be within 90°, which is the only necessary condition for the feedback unconstrained FxLMS. The significance of the analysis on a practical system is also discussed. Finally we show how the obtained results can guide us to design a robust feedback ANC headset.

Interfaces cérebro-computador: estudo, design e desenvolvimento do jogo AdmiralMind Battleship

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