We study adaptive-playout scheduling for Voice over IP using the frame-work of stochastic impulse control theory. We use the Wiener process tomodel the fluctuation of the buffer length in the absence of control. In thiscontext, the control signal consists of length units that correspond to insert-ing or dropping a pitch cycle. We define an optimality criterion that hasan adjustable trade-off between average buffering delay and average controlsignal (the length of the pitch cycles added plus the length of the pitch cyclesdropped), and show that a band control policy is optimal for this criterion.The band control policy maintains the buffer length within a band regionby imposing impulse control (inserted or dropped pitch cycles) whenever thebounds of the band are reached. One important property of the band controlpolicy is that it incurs no packet-loss through buffering if there are no out-of-order packet-arrivals. Experiments performed on both synthetic and realnetwork-delay traces show that the proposed playout scheduling algorithmoutperforms two recent algorithms in most cases.
In the future, everyday life in traffic will be intricately meshed with city life. Today, motorways, city streets, toll roads, country roads, etc. are places where we spend a considerable amount of time, and where a large number of everyday encounters between people occur. Any road user’s journey coincides with several, sometimes hundreds or even thousands of other people’s journeys. But these encounters are brief and the interaction is slight. Mobile technologies and emergent social media provide us with new possibilities to support drivers and passengers beyond just helping them to reach their destination. We suggest that new technologies and applications could enhance social interaction in traffic and make life on the road more interesting and meaningful
The importance of including contact expressions in different kinds of devices is discussed. The technical development of sensor-motor systems, tactile interfaces, and contact-expressive devices that embody and understand affect are also discussed. The existing attempts to describe human contact tend to be attempts to create general descriptive taxonomies. The development of semiotic models of imagery has helped in designing visual interfaces.
Contact-expressive devices could improve our lives -- from practical improvements that let us interact with devices when other modalities are impossible, inappropriate, or inadequate to devices that have important consequences for physical well-being. We can also imagine using contact expressions in devices that are pleasurable, playful, artistic, or otherwise important to a human's experience. This paper discusses the technical development of sensor-motor systems, tactile interfaces, and technologies that can embody and understand affect. Contact-expressive devices are technologies that understand and use touch in meaningful ways-that can distinguish between a press and a caress. Also discussed are the following issues: technical requirements and the nature of contact expressions. Although a fairly large body of research exists regarding nonverbal communication, the majority of this work is on visual expression (facial expressions, physical appearance, direction of gaze, physical posture, and other visible forms of body language) and paralinguistics (such as vocal inflection, pitch, volume, and speech rate). Work needs to begin on studies of human contact with the goal of leveraging those insights for the design of contact-expressive devices-and work needs to begin on the implementation of technologies that have rich contact-expressive range and appeal.
Interactive systems, virtual environments, and information display applications need dynamic sound models rather than faithful audio reproductions. This implies three levels of research: auditory perception, physics-based sound modeling, and expressive parametric control. Parallel progress along these three lines leads to effective auditory displays that can complement or substitute visual displays.
In the context of 3D video systems, depth information could be used to render a scene from additional viewpoints. Although there have been many recent advances in this area, including the introduction of the Microsoft Kinect sensor, the robust acquisition of such information continues to be a challenge. This article reviews three depth-sensing approaches for 3DTV. The authors discuss several approaches for acquiring depth information and provides a comparative analysis of their characteristics.
Obstructive Sleep Apnea (OSA) is one of the most common sleep-related breathing disorders. Nearly 1 billion people worldwide suffer from it, causing serious health effects and social burden. However, traditional monitoring systems often fall short in terms of cost and accessibility. In this article, we first propose a deep active learning model to detect OSA events from electrocardiogram (ECG). We then designed and developed a prototype of OSA monitoring system using ECG sensor and smartphone, in which our OSA detection algorithm is implemented and validated. Experiments show that we achieve accuracy of 92.15% while using 40% of labeled data, significantly reducing the cost of labeling and maximizing the performance. According to detection results and health-related multimedia signals, we provide OSA risk level and medical advice to users. We believe that the multimedia monitoring system can efficiently help diagnose OSA, which could lead to effective intervention strategies and better sleep care.