ARBITER: Adaptive rate-based intelligent HTTP streaming algorithm

Dynamic Adaptive streaming over HTTP (DASH) is widely used by content providers for video delivery and dominates traffic on cellular networks. The inherent variability in both video bitrate and network bandwidth negatively impacts the user Quality of Experience (QoE), motivating the design of better DASH-compliant adaptation algorithms. In this paper we present ARBITER, a novel streaming adaptation algorithm that explicitly integrates the variations in both video and network dynamics in its adaptation decisions. Our simulation-based performance evaluation, using real video content and cellular bandwidth traces, shows that ARBITER achieves an excellent tradeoff among streaming metrics in terms of received video quality, stall count, stall duration, and switching dynamics, leading to a relative improvement of 17-45% in user QoE in comparison to state-of-the-art algorithms

A RESTful API for exchanging Materials Data in the AFLOWLIB.org consortium

The continued advancement of science depends on shared and reproducible data. In the field of computational materials science and rational materials design this entails the construction of large open databases of materials properties. To this end, an Application Program Interface (API) following REST principles is introduced for the AFLOWLIB.org materials data repositories consortium. AUIDs (Aflowlib Unique IDentifier) and AURLs (Aflowlib Uniform Resource locator) are assigned to the database resources according to a well-defined protocol described herein, which enables the client to access, through appropriate queries, the desired data for post-processing. This introduces a new level of openness into the AFLOWLIB repository, allowing the community to construct high-level work-flows and tools exploiting its rich data set of calculated structural, thermodynamic, and electronic properties. Furthermore, federating these tools would open the door to collaborative investigation of the data by an unprecedented extended community of users to accelerate the advancement of computational materials design and development.Comment: 22 pages, 7 figure

Shifting the EU Taxonomy from Theory to Practice: A Review of the Literature highlighting Potential Academic Contributions to its Adoption, Implementation, and Impact

The EU Taxonomy seeks to identify those sustainable economic activities, thereby supporting climate change mitigation and adaptation. Recent legislation underpinning the EU Taxonomy, such as the Non-Financial Reporting Directive (NFRD) and the Sustainable Finance Disclosure Regulation (SFDR), highlight the urgency for academic contributions that might shed light on its operationalisation. At this embryonic stage in the Taxonomy’s lifecycle, there is potential for the academic community to contribute to understanding its implications. Hence, we undertake a thematic analysis of predominantly, but not exclusively, professional literature to prioritise potential empirical research or conceptualisations that might offer insights for finance and accounting professionals, regulators, policymakers, investors and businesses. Our literature search is limited to literature that makes explicit reference to the Taxonomy between 2018 and 2021. We find that little is understood on how investors or businesses intend to disclose against the taxonomy or on the challenges associated with disclosure. With sustainable finance emerging in Ireland, we propose an exploratory study of this sector’s readiness to operationalise the taxonomy and offer a conceptual framework based on co-evolution theory (Foxon, 2011) bounded by three initial conditions: [1] skills and capability and [2] access to ESG data and [3] regulatory alignment

Sizing network buffers: an HTTP Adaptive Streaming perspective

HTTP Adaptive video Streaming (HAS) is the dominant traffic type on the Internet. When multiple video clients share a bottleneck link many problems arise, notably bandwidth underutilisation, unfairness and instability. Key findings from previous papers show that the "ON-OFF" behaviour of adaptive video clients is the main culprit. In this paper we focus on the network, and specifically the effects of network queue size when multiple video clients share network resources. We conducted experiments using the Mininet virtual network environment streaming real video content to open-source GPAC video clients. We explored how different network buffer sizes, ranging from 1xBDP to 30xBDP (bandwidth-delay-product), affect clients sharing a bottleneck link. Within GPAC, we implemented the published state-of-the-art adaptive video algorithms FESTIVE and BBA-2. We also evaluated impact of web cross-traffic. Our main findings indicate that the "rule-of-thumb" 1xBDP for network buffer sizing causes bandwidth underutilisation, limiting available bandwidth to 70% for all video clients across different round-trip-times (RTT). Interaction between web and HAS clients depends on multiple factors, including adaptation algorithm, bitrate distribution and offered web traffic load. Additionally, operating in an environment with heterogeneous RTTs causes unfairness among ompeting HAS clients. Based on our experimental results, we propose 2xBDP as a default network queue size in environments when multiple users share network resources with homogeneous RTTs. With heterogeneous RTTs, a BDP value based on the average RTTs for all clients improves fairness among competing clients by 60%

Prototyping and evaluating SDN-based multicast architectures for live video streaming [Demo]

Software Defined Networking (SDN) is an emerging approach for network programmability, with the capacity to initialize, control, change, and manage network behavior dynamically via open interfaces. The rise of SDN presents an opportunity to overcome the limitations of rigid and static traditional Internet architecture and provide services like inter-domain network layer multicast for live video streaming. In this demonstration we present a platform to evaluate and compare SDN-based multicast architectures for live streaming and benchmark their performance against standard IP unicast. The platform is equipped with two graphical user interfaces (GUI). A Panoramic UI provides a mechanism to modify various evaluation parameters and monitor the effect on output in form of graphs and live statistics. An Animator UI displays traffic flows over the chosen network topology and offers packet level information for the ongoing video streams. We also present a prototype of mCast implemented on our platform. mCast is a novel SDN-based multicast architecture for live video streaming over the Internet. The feedback from our platform and its GUIs showcases how mCast can save network and system resources while improving the video quality for clients

mCast: An SDN-based resource-eficient live video streaming architecture with ISP-CDN collaboration

The rise of Software Defined Networking (SDN) presents an opportunity to overcome the limitations of rigid and static traditional Internet architecture and provide services like network layer multicast for live video streaming. In this paper we propose mCast, an SDN-based architecture for live streaming, to reduce the utilization of network and system resources for both Internet Service Providers (ISP) and Content Delivery Networks (CDN) by using multicast over the Internet. We propose a communication framework between ISPs and CDNs to enable mCast while retaining user and data privacy. mCast is transparent to the clients and maintains the control of CDNs on user sessions. We developed a testbed and performed large scale evaluation and comparison. Results showed that mCast can improve the video quality received by clients and, for CDNs and ISPs in comparison to IP unicast, mCast can decrease link utilization by more than 50% and network losses to 0%

Datasets for AVC (H.264) and HEVC (H.265) evaluation of dynamic adaptive streaming over HTTP (DASH)

In this paper we present datasets for both trace-based simulation and real-time testbed evaluation of Dynamic Adaptive Streaming over HTTP (DASH). Our trace-based simulation dataset provides a means of evaluation in frameworks such as NS-2 and NS-3, while our testbed evaluation dataset offers a means of analysing the delivery of content over a physical network and associated adaptation mechanisms at the client. Our datasets are available in both H.264 and H.265 with encoding rates comparative to the representations and resolutions of content distribution providers such as Netflix, Hulu and YouTube. The goal of our dataset is to provide researchers with a sufficiently large dataset, in both number, and duration, of clips which provides a comparison between both encoding schemes. We provide options for evaluating not only different content and genres, but also the underlying encoding metrics, such as transmission cost, segment distribution (the range of the oscillation of the segment sizes) and associated delivery issues such as jitter and re-buffering. Finally, we also offer our datasets in a header-only compressed format, which allows researchers to download the entire dataset and uncompress locally, thus ensuring that our datasets are accessible both online via remote and local servers

Design of a Professional Development Framework in Teaching and Learning for Engineering Educators

Ireland’s National Professional Development Framework for Those who Teach in Higher Education, aims to provide guidance and leadership in the planning, developing and engaging in professional development practices. A series of pilot projects have been initiated to help explore the framework’s likely utility and acceptance by educators and their institutions. These projects require engagement with staff in the interpretation and adaption of the framework within their working contexts. The purpose of this paper is to outline the development of one such project with engineering educators at three Institutes of Technology seeking designation as a technological university. The initiative aims to gain traction in the acceptance of the framework with the engineering education community by linking core and discipline-specific teaching and learning competencies with professional development activities most valued by engineering educators. Informed by three strands of literature: professional development in higher education; engineering education; and teaching and learning training provisions, the project begins with a survey of all those involved in teaching and learning in engineering across the three institutes. Based on engagement with key stakeholders, subsequent qualitative research informs the contextualization of the national framework for discipline-specific and institutional piloting. The paper concludes by exploring engineering educator perceptions of the national framework’s utility based on their engagement with the pilot process. Feedback from the pilot indicates that there is a significant gap between the professional development needs of engineering educators and the current professional development provision in teaching and learning

Empowering Responsible and Sustainability-Aware Business Graduates Through Digital Authentic Assessment

Business schools must engage in fundamental change to retain their legitimacy and position themselves as providers of solutions to urgent economic, social and environmental crises. Achievement of the UN Sustainable Development Goals (SDGs) has emerged as a megatrend and business education must enhance graduate skills to contribute to their achievement. The world requires the next generation of graduates to become responsible business leaders who will address wicked sustainability problems. Hence, we need pedagogy that enables students to become sustainability literate and thus develop appropriate knowledge, skills and mindsets. Authentic assessment provides transformative learning opportunities that empower students to achieve meaningful impact in the real world. Despite some recent research that connects authentic assessment and sustainability, there is a dearth of empirical research on authentic assessments for sustainability in business disciplines. We outline a pedagogical initiative designed with the aim of enhancing sustainability literacy among business students using innovative digital tools as part of authentic assessment strategy. We designed and implemented authentic assessment strategies that engage students with learning across a number of different delivery modes and in a ‘deep’ reflective manner with meaningful tasks. Business students on undergraduate, postgraduate and executive programmes follow the same format with some adjustments made to reflect the different discipline/module focus. This includes completion of: (i) a sustainability literacy test through the UN supported Sulitest platform, (ii) a written reflection on learning, stemming from the Sulitest that utilises the DIEP reflective model, (iii) the creation of digital artefacts such as a short video shared on LinkedIn; student activism involving contacting political representatives/brands; creation of social media content in partnership with sustainability-focused organisations; podcasts with invited guests; writing of opinion pieces for media; and creation of e-portfolios that showcase students\u27 work. We believe this deep reflection and awareness signposts efficacious action emerging from our transformative learning pedagogy, based digital authentic assessment design. This pedagogical approach equips students with sustainability-specific knowledge, global citizenship skills, digital skills, and creative and inquisitive mindsets

AFLOW-SYM: Platform for the complete, automatic and self-consistent symmetry analysis of crystals

Determination of the symmetry profile of structures is a persistent challenge in materials science. Results often vary amongst standard packages, hindering autonomous materials development by requiring continuous user attention and educated guesses. Here, we present a robust procedure for evaluating the complete suite of symmetry properties, featuring various representations for the point-, factor-, space groups, site symmetries, and Wyckoff positions. The protocol determines a system-specific mapping tolerance that yields symmetry operations entirely commensurate with fundamental crystallographic principles. The self consistent tolerance characterizes the effective spatial resolution of the reported atomic positions. The approach is compared with the most used programs and is successfully validated against the space group information provided for over 54,000 entries in the Inorganic Crystal Structure Database. Subsequently, a complete symmetry analysis is applied to all 1.7$+$ million entries of the AFLOW data repository. The AFLOW-SYM package has been implemented in, and made available for, public use through the automated, $\textit{ab-initio}$ framework AFLOW.Comment: 24 pages, 6 figure