OpenCRP Ecosystem Demonstration Platform

AbstractMobile robots with service-oriented functions are stepping to our lives in hospitals, hospices and industries where robots can help to assist or perform all the arduous working duties. A lot of laborious processes are found that can be automatized, e.g. in hospital medicine delivery and food servery to ward for patients. This paper presents a pilot- and demonstration environment for multiple open-source mobile robots sharing their collected data with each other via a private cloud. The presented platform, OpenCRP, introduces a novel ecosystem based on an open-source software frameworks and robots

Hammerstein Model for Speech Coding

<p/> <p>A nonlinear Hammerstein model is proposed for coding speech signals. Using Tsay's nonlinearity test, we first show that the great majority of speech frames contain nonlinearities (over 80% in our test data) when using 20-millisecond speech frames. Frame length correlates with the level of nonlinearity: the longer the frames the higher the percentage of nonlinear frames. Motivated by this result, we present a nonlinear structure using a frame-by-frame adaptive identification of the Hammerstein model parameters for speech coding. Finally, the proposed structure is compared with the LPC coding scheme for three phonemes /a/, /s/, and /k/ by calculating the Akaike information criterion of the corresponding residual signals. The tests show clearly that the residual of the nonlinear model presented in this paper contains significantly less information compared to that of the LPC scheme. The presented method is a potential tool to shape the residual signal in an encode-efficient form in speech coding.</p

Congestion Control Supported Dual-Mode Video Transfer

Transfer of videos over the Internet has increased considerably during the past decade and recent studies indicate that video services represent over half of the Internet traffic, with a growing trend. For the user-friendly operation of the Internet, it is important to distribute these videos in a proper and efficient way. However, no congestion control mechanism suitable and widely used for all kinds of video services is available. We have developed a congestion control mechanism, which is particularly suitable for long-living video traffic. The advantage of the proposed mechanism is its dual-priority nature. There is a mode for low priority traffic where the bandwidth is given away to other connections after the load level of a network exceeds a certain level. On the other hand, the real-time mode of the mechanism acquires its fair share of the network capacity. The real network tests of this study verify the proper operation of our congestion control mechanism.acceptedVersionPeer reviewe