Subjective Quality Assessment of the Impact of Buffer Size in Fine-Grain Parallel Video Encoding

Fine-Grain parallelism is essential for real-time video encoding performance. This usually implies setting a fixed buffer size for each encoded block. The choice of this parameter is critical for both performance and hardware cost. In this paper we analyze the impact of buffer size on image subjective quality, and its relation with other encoding parameters. We explore the consequences on visual quality, when minimizing buffer size to the point of causing the discard of quantized coefficients for highest frequencies. Finally, we propose some guidelines for the choice of buffer size, that has proven to be heavily dependent, in addition to other parameters, on the type of sequence being encoded. These guidelines are useful for the design of efficient realtime encoders, both hardware and software

Mobile Communication Networks and Digital Television Broadcasting Systems in the Same Frequency Bands – Advanced Co-Existence Scenarios

The increasing demand for wireless multimedia services provided by modern communication systems with stable services is a key feature of advanced markets. On the other hand, these systems can many times operate in a neighboring or in the same frequency bands. Therefore, numerous unwanted co-existence scenarios can occur. The aim of this paper is to summarize our results which were achieved during exploration and measurement of the co-existences between still used and upcoming mobile networks (from GSM to LTE) and digital terrestrial television broadcasting (DVB) systems. For all of these measurements and their evaluation universal measurement testbed has been proposed and used. Results presented in this paper are a significant part of our activities in work package WP5 in the ENIAC JU project “Agile RF Transceivers and Front-Ends for Future Smart Multi-Standard Communications Applications (ARTEMOS)”

Testing QoE in Different 3D HDTV Technologies

The three dimensional (3D) display technology has started flooding the consumer television market. There is a number of different systems available with different marketing strategies and different advertised advantages. The main goal of the experiment described in this paper is to compare the systems in terms of achievable Quality of Experience (QoE) in different situations. The display systems considered are the liquid crystal display using polarized light and passive lightweight glasses for the separation of the left- and right-eye images, a plasma display with time multiplexed images and active shutter glasses and a projection system with time multiplexed images and active shutter glasses. As no standardized test methodology has been defined for testing of stereoscopic systems, we develop our own approach to testing different aspects of QoE on different systems without reference using semantic differential scales. We present an analysis of scores with respect to different phenomena under study and define which of the tested aspects can really express a difference in the performance of the considered display technologies

Simulation and Measurement of the Transmission Distortions of the Digital Television DVB-T/H Part 3: Transmission in Fading Channels

The paper deals with the third (and last) part of results of the Czech Science Foundation research project that was aimed into the simulation and measurement of the transmission distortions of the digital terrestrial television according to DVB-T/H standards. In this part the transmission of the digital television according to DVB-T/H standard over the fading channels and their models and profiles for fixed, portable and mobile reception is analyzed. Impact of the fading channels and their models on Modulation Error Rate from I/Q constellations and Bit Error Rates before and after Viterbi decoding in DVB-T/H signal decoding is presented

Ökonomische Aspekte einer großflächigen Bewirtschaftung nach den Prinzipien des Ökologischen Landbaus dargestellt am Beispiel der Region Mostviertel-Eisenwurzen (Ö)

In der Diskussion um die Vorteilhaftigkeit des Ökologischen Landbaus wird häufig das Argument gebraucht, dass der Biolandbau gegenüber der konventionellen Landwirtschaft betriebswirtschaftliche Vorteile aufweist und darüber hinaus deutlich geringere externe Kosten verursacht, so dass auch aus volkswirtschaftlicher Sicht Vorteile bestehen. Im Zuge des zugrunde liegenden Forschungsprojektes wird daher geprüft, inwieweit sich eine Umstellung auf den Biolandbau sowohl auf ausgewählte betriebswirtschaftliche Parameter (Deckungsbeitrag, Beschäftigung), als auch auf ökologische Kenngrößen (Treibhausgasemissionen, Wasserqualität) und damit auf die externen Kosten auswirkt. In diesem Beitrag ist dargestellt, zu welchen Veränderungen eine Umstellung in der Region Mostviertel-Eisenwurzen (Ö) auf die Höhe des Deckungsbeitrags bei Milchviehbetrieben führt und inwieweit die externen Kosten infolge der Treibhausgasemissionen gesenkt werden können

Depth Map Improvement by Combining Passive and Active Scanning Methods

The paper presents a new method of more precise estimation of the depth map in 3D videos. The novelty of the proposed approach lies in sophisticated combination of partial results obtained by selected existing passive and active 3D scanning methods. The aim of the combination is to overcome drawbacks of individual methods and this way to improve the accessible precision of the final depth map. The active method used is incoherent profilometry scanning which fails on surface discontinuities. As a passive method, a stereo pair matching is used. This method is currently the most widely applied method of depth map estimation in the field of 3D capturing and is available in various implementations. Unfortunately, it fails if there is a lack of identifiable corresponding points in the scanned scene. The paper provides a specific way of combining these methods to improve the accuracy and usability. The proposed innovative technique exploits the advantages of both approaches. Specifically, the more accurate depth profiles of individual discontinuous objects obtained from the active method, and information about mean depths of the objects from the stereo pair are combined. Two implementations of the passive method have been tested for combination with active scanning: matching from stereo pair, and SIFT. The paper includes a brief description of the active and passive methods used and a thorough explanation of their combination. As an example, the proposed method is tested on a simple scene whose nature enables straight assessment of the achieved accuracy. The choice of a suitable implementation of the passive component is also shown and discussed. The obtained results of individual existing methods used and of the proposed combined method are given and compared. To demonstrate the contribution of the proposed combined method, also a comparison with the results obtained with a commercial solution is presented with significantly good results

Effective eModule Design for First-Year Medical Student Anatomy Curricula

Introduction: It is critical to evaluate student experience with any newly integrated educational resource. In 2018, a Distal Upper Limb (DUL) Anatomy eModule was developed for first-year medical students at the University of Nebraska Medical Center, who have historically identified the DUL as a region of difficulty. This mixed methods study sought to (1) evaluate learner perception of the eModule relative to other resources, and (2) identify eModule content and features that students found valuable. Methods: The DUL eModule was made available to first-year medical students in 2019 (n= 132), 2020 (n=131), and 2021 (n=131) as a voluntary, supplemental resource. In 2019-2021, all eModule users were prompted to complete a post-eModule, pre-exam survey. In 2021, users were also asked to complete a post-eModule, post-exam survey. Both surveys included a combination of Likert-type and free-response questions. Results: In the post-eModule, pre-exam survey, a majority of students from all three years agreed or strongly agreed that the eModule was convenient, preferred compared to a textbook or didactic lecture, and applicable to the gross anatomy lab, though opinions were more split when comparing the eModule to studying from a gross specimen. In the post-eModule, post-exam survey, greater than 75% of students agreed or strongly agreed that the eModule prepared them to answer DUL exam questions, and was a useful adjunct to learning DUL anatomy. In the survey’s free response section, students cited support for the eModule’s cadaveric images, its ability to consolidate/organize information, and its two modes of use, though users reported a need for a figure legend to orient the user, and a desire for a learning evaluation integrated within the eModule. Discussion: While gross anatomy has historically been taught through in-person dissection, student demand for digital, remote learning resources is certain to grow. The findings of this mixed methods analysis will serve to guide anatomy faculty in developing effective digital resources for future novice anatomists.https://digitalcommons.unmc.edu/emet_posters/1034/thumbnail.jp

Wi-Fi Influence on LTE-U Downlink Data and Control Channel Performance in Shared Frequency Bands

Nowadays, providers of wireless services try to find appropriate ways to increase user data throughput mainly for future 5G cellular networks. Utilizing the unlicensed spectrum (ISM bands) for such purpose is a promising solution: unlicensed frequency bands can be used as a complementary data pipeline for UMTS LTE (Universal Mobile Telecommunication System - Long Term Evolution) and its advanced version LTE-Advanced, especially in pico- or femtocells. However, coexisting LTE and WLAN services in shared ISM bands at the same time can suffer unwanted performance degradation. This paper focuses predominantly on co-channel coexistence issues (worst case) between LTE and WLAN (IEEE 802.11n) services in the ISM band. From the viewpoint of novelty, the main outcomes of this article are follows. Firstly, an appropriate signal processing approach for coexisting signals with different features in the baseband is proposed. It is applied in advanced link-layer simulators and its correctness is verified by various simulations. Secondly, the influence of IEEE 802.11n on LTE data and control channel performance is explored. Performance evaluation is based on error rate curves, depending on Signal-to-Interference ratio (SIR). Presented results allow for better understanding the influence of IEEE 802.11n on the LTE downlink physical control channels (PCCH) and are valuable for mobile infrastructure vendors and operators to optimize system parameters

Photovoltaic array performance model.

This document summarizes the equations and applications associated with the photovoltaic array performance model developed at Sandia National Laboratories over the last twelve years. Electrical, thermal, and optical characteristics for photovoltaic modules are included in the model, and the model is designed to use hourly solar resource and meteorological data. The versatility and accuracy of the model has been validated for flat-plate modules (all technologies) and for concentrator modules, as well as for large arrays of modules. Applications include system design and sizing, 'translation' of field performance measurements to standard reporting conditions, system performance optimization, and real-time comparison of measured versus expected system performance