Constructing a no-reference H.264/AVC bitstream-based video quality metric using genetic programming-based symbolic regression

In order to ensure optimal quality of experience toward end users during video streaming, automatic video quality assessment becomes an important field-of-interest to video service providers. Objective video quality metrics try to estimate perceived quality with high accuracy and in an automated manner. In traditional approaches, these metrics model the complex properties of the human visual system. More recently, however, it has been shown that machine learning approaches can also yield competitive results. In this paper, we present a novel no-reference bitstream-based objective video quality metric that is constructed by genetic programming-based symbolic regression. A key benefit of this approach is that it calculates reliable white-box models that allow us to determine the importance of the parameters. Additionally, these models can provide human insight into the underlying principles of subjective video quality assessment. Numerical results show that perceived quality can be modeled with high accuracy using only parameters extracted from the received video bitstream

Research in cosmic and gamma ray astrophysics

Research activities in cosmic rays, gamma rays, and astrophysical plasmas are covered. The activities are divided into sections and described, followed by a bibliography. The astrophysical aspects of cosmic rays, gamma rays, and of the radiation and electromagnetic field environment of the Earth and other planets are investigated. These investigations are performed by means of energetic particle and photon detector systems flown on spacecraft and balloons

Hands-On: Experiencing Software Architecture in Virtual Reality

Recently, virtual reality (VR) and gesture-based interface devices emerged at the consumer market. Both concepts offer new visualization and interaction capabilities, which can improve the user experience when using software. In Software Engineering, exploring and comprehending software systems is often addressed via visualization techniques. In this paper, we present our VR approach to explore software systems by using a head-mounted display and two different gesture-based interaction devices. Hence, we achieve a more immersive user experience and natural interaction, which benefits the comprehension process. Our VR approach is integrated into ExplorViz, our tool for live trace visualization of large software landscapes. In order to emphasize the advantages, we apply our combined approach on a small software system, running within our webbased tool ExplorViz. In this context, we present both, the visualization and the interaction capabilities

RRS Discovery Cruise 248, 07 Jul-10 Aug 2000. A multidisciplinary study of the environment and ecology of deep-water coral ecosystems and associated seabed facies and features (The Darwin Mounds, Porcupine Bank and Porcupine Seabight)

RRS Discovery Cruise 248 aimed to carry out a multidisciplinary study of the environment and ecology of deep-water coral ecosystems and associated seabed features in the northeast Atlantic. The study was primarily focused on the Darwin Mounds area, northern Rockall Trough (59° 49’N, 07° 22’W), but also examined a number of sites in the Porcupine Seabight area. The cruise was divided into two legs (Govan-Stornoway, 8 Jul-21 Jul 2000; Stornoway-Southampton, 22 Jul-10 Aug 2000). Leg 1 focused on the ecology of the Darwin Mounds area, with seabed photographic surveys (SOC SHRIMP system), coring (Box and Multiple cores) and trawling (Agassiz) forming the main activities. Leg 2 began with detailed geological investigations of the Darwin Mounds area, concentrating on piston coring and sidescan sonar surveys. Leg 2 concluded with combined ecological and geological studies of carbonate mound sites on the Porcupine Bank and in the Porcupine Seabight.Observations in the Darwin Mounds area confirmed the common occurrence of deep-water corals on these Mounds. The mounds themselves do not appear to be carbonate formations but may be better characterised as sand volcanoes. Numerous xenophyophores were observed in association with the mounds; however, no live specimens were recovered in any of the samples collected. Sidescan sonar images and seabed photography both suggested that the Darwin Mounds area had been subject to considerable commercial trawling with resultant apparent damage to the deep-water coral ecosystems.The various operations undertaken in the Porcupine Seabight area were also successful in imaging giant carbonate mounds and their associated coral communities with both sidescan sonar and seabed photography, and in recovering biological sample material from these areas. In common with the Darwin Mounds area, the observations made suggested that deep-water fishing impacts on coral ecosystems were also evident in this region

Network Performance Criteria for Telecommunication Traffic Types driven by Quality of Experience

A common reason for changing the chosen service provider is the users\u27 perception of service. Quality of Experience (QoE) describes the end user\u27s perception of service while using it. A frequent cause of QoE degradation is inadequate traffic routing, where, other than throughput, selected routes do not satisfy minimum network requirements for the given service or services. In order to enable QoE-driven routing, per traffic type defined routing criteria are required. Our goal was to obtain those criteria for relevant services of a telecom operator. For the purpose of identifying services of interest, we first provide short results of user traffic analysis within the telecom operator network. Next, our work presents testbed measurements which explore the impact of packet loss and delay on user QoE for video, voice, and management traffic. For video services, we investigated separately multicast delivery, unicast HTTP Live Streaming (HLS), and unicast Real Time Streaming Protocol (RTSP) traffic. Applying a threshold to QoE values, from the measured dependencies we extracted minimum network performance criteria for the investigated different types of traffic. Finally, we provide a comparison with results available in the literature on the topic