Dynamic water fill level measurement using a phantom-dependent adaptive electrical capacitance tomography (ECT) method

In electrical capacitance tomography (ECT), the resolution of the reconstructed permittivity distribution improves with the number of electrodes used whereas the number of capacitance measurements and the measurement time increases with the number of electrodes. To cope with this tradeoff, we present a phantom-dependent adaptation scheme in which coarse measurements are performed with terminal electrodes interconnected to form a synthetic electrode ring with fewer but larger electrodes. The concept was tested by observing the sloshing of water inside a pipe. We compare the reconstructed results based on eight synthetic electrodes, on 16 elementary electrodes, and on the adaptation scheme involving both the eight synthetic electrodes and some of the elementary capacitances. The reconstruction used the projected Landweber algorithm for capacitances determined by a finite-element simulation and for measured capacitances. The results contain artefacts attributed to the influence of the high permittivity of water compared to the low permittivity of the pipe wall. The adaptation scheme leads to nearly the same information as a full measurement of all 120 elementary capacitances but only requires the measurement of 30 % fewer capacitances. By detecting the fill level using a tomometric method, it can be determined within an uncertainty of 5 % FS.

Buffer-based rate adaptation scheme for HTTP video streaming with consistent quality

Recently, HyperText Transfer Protocol (HTTP) based adaptive streaming (HAS) has been proposed as a solution for efficient use of network resources. HAS performs rate adaptation that adjusts the video quality according to the network conditions. The conventional approaches for rate adaptation involve accurately estimating the available bandwidth or exploiting the playback buffer in HAS clients rather than estimating the network bandwidth. In this paper, we present a playback buffer model for rate adaptation and propose a new buffer-based rate adaptation scheme. First, we model the playback buffer as a queueing system that stores video segments. The proposed scheme selects the next video bitrate that minimizes the difference between the current buffer occupancy and the expected value from the playback buffer model. The evaluation results indicated that the proposed scheme achieves higher video quality than conventional algorithms and can cope with various environments without the tuning of the configuration parameters.

ARQ: The Gateway from NOMA to NOM

<div>This work presents a new framework that utilizes</div><div>power-domain (PD) nonorthogonal multiple access (NOMA) as a multiplexing scheme to improve the throughput of point-to-point (P2P), or single user, communications. The proposed framework synergizes PD-NOMA and automatic repeat request (ARQ) to enable multiplexing and transmitting multiple packets that belong to the same user simultaneously. To overcome channel estimation and feedback limitations, and to reduce the system complexity, a simple adaptation scheme is proposed select the</div><div>appropriate number packets to be transmitted within a given</div><div>transmission slot. Moreover, the number of transmitted packets</div><div>is limited to a maximum of two to allow the receiver to blindly</div><div>identify the number of transmitted packets in a particular</div><div>transmission slot. The obtained results show that the proposed</div><div>NOM scheme can eventually double the system throughput at</div><div>high signal-to-noise ratios (SNRs), and hence, reduce the delay</div><div>by 50%. The system complexity and overhead are generally</div><div>comparable to conventional ARQ systems.</div>

ARQ: The Gateway from NOMA to NOM

<div>This work presents a new framework that utilizes</div><div>power-domain (PD) nonorthogonal multiple access (NOMA) as a multiplexing scheme to improve the throughput of point-to-point (P2P), or single user, communications. The proposed framework synergizes PD-NOMA and automatic repeat request (ARQ) to enable multiplexing and transmitting multiple packets that belong to the same user simultaneously. To overcome channel estimation and feedback limitations, and to reduce the system complexity, a simple adaptation scheme is proposed select the</div><div>appropriate number packets to be transmitted within a given</div><div>transmission slot. Moreover, the number of transmitted packets</div><div>is limited to a maximum of two to allow the receiver to blindly</div><div>identify the number of transmitted packets in a particular</div><div>transmission slot. The obtained results show that the proposed</div><div>NOM scheme can eventually double the system throughput at</div><div>high signal-to-noise ratios (SNRs), and hence, reduce the delay</div><div>by 50%. The system complexity and overhead are generally</div><div>comparable to conventional ARQ systems.</div>