Because computers may contain or interact with sensitive information, they are often airgapped and in this way kept isolated and disconnected from the Internet. In recent years the ability of malware to communicate over an air-gap by transmitting sonic and ultrasonic signals from a computer speaker to a nearby receiver has been shown. In order to eliminate such acoustic channels, current best p...

In this paper, a new digital intermediate frequency modulator for conventional TV signals using digital signal processing is presented. A composite colour video signal and two associated audio signals are converted into a digital composite TV signal with spectrum at intermediate frequency. The modulator is designed for the high quality requirements that exist in professional equipment for CATV ...

Dielectrics and dielectric properties are defined generally and dielectric measurement methods and equipment are described for various frequency ranges from audio frequencies through microwave frequencies. These include impedance and admittance bridges, resonant frequency, transmission-line, and free-space methods in the frequency domain and time-domain and broadband techniques. Many references...

We charaterize a workload of media-enhanced classrooms. Such classrooms include equipment for presenting multimedia streams and for capturing streams of information (audio, video and notes) during a lecture. We present detailed quantitative performance measurements of one media-enhanced classroom system , Classroom 2000. We characterize the workload from the point of view of a server that suppo...

reading-rm/doc-collections/ (ACRS & ACNW Mtg schedules/agendas). Videoteleconferencing service is available for observing open sessions of ACRS meetings. Those wishing to use this service for observing ACRS meetings should contact Mr. Theron Brown, ACRS Audio Visual Technician (301–415–8066), between 7:30 a.m. and 3:45 p.m., e.t., at least 10 days before the meeting to ensure the availability o...

The individual cognitive science disciplines all have contributions to make to the understanding and modelling of human learning. Our previous research has explored unsupervised learning of phonology, morphology and low-level syntax, as well as basic noun, verb and preposition ontology and semantics, plus musical and speech prosody. Successful applications using a mix of supervised and unsuperv...

A flexible, scalable and affordable virtual reality software system architecture is proposed. This solution can be easily implemented on different hardware configurations: on a single computer or on a computer cluster. The architecture is aimed to be integrated in the workflow for solving engineering tasks and oriented towards presenting implicit object properties through multiple sensorial cha...

Here we present an overview of a system we are developing for animating faces using appearance models. To facilitate more widespread use of animated characters, we are interested in developing techniques that: 1) require only easy to use and inexpensive data capture equipment, 2) are threedimensional allowing virtual characters to be animated, 3) allow a range of face models, from near-photorea...

This research focuses on the relationship between turntaking and intensity of motions (head, hand and upper body motions). We examine five spontaneous dialogues conducted in Japanese, which were collected using video and audio recording equipment, and optical motion sensing device. We show first that the motions appear more in speech duration than in pause. Next, we present some data showing th...

1. ABSTRACT The use of envelope detection methods to reduce the bandwidth of an echolocation click into the audio-band is not a new concept. However, the increasing popularity of portable digital recorders with excellent signal to noise performance needs such signal processing if ultrasonic transient data needs to be captured. Similarly, this approach allows high frequency information to be rec...