Sample-Parallel Execution of EBCOT in Fast Mode

JPEG 2000’s most computationally expensive building block is the Embedded Block Coder with Optimized Truncation (EBCOT). This paper evaluates how encoders targeting a parallel architecture such as a GPU can increase their throughput in use cases where very high data rates are used. The compression efficiency in the less significant bit-planes is then often poor and it is beneficial to enable the Selective Arithmetic Coding Bypass style (fast mode) in order to trade a small loss in compression efficiency for a reduction of the computational complexity. More importantly, this style exposes a more finely grained parallelism that can be exploited to execute the raw coding passes, including bit-stuffing, in a sample-parallel fashion. For a latency- or memory critical application that encodes one frame at a time, EBCOT’s tier-1 is sped up between 1.1x and 2.4x compared to an optimized GPU-based implementation. When a low GPU occupancy has already been addressed by encoding multiple frames in parallel, the throughput can still be improved by 5% for high-entropy images and 27% for low-entropy images. Best results are obtained when enabling the fast mode after the fourth significant bit-plane. For most of the test images the compression rate is within 1% of the original

Evaluation of GPU/CPU Co-Processing Models for JPEG 2000 Packetization

With the bottom-line goal of increasing the throughput of a GPU-accelerated JPEG 2000 encoder, this paper evaluates whether the post-compression rate control and packetization routines should be carried out on the CPU or on the GPU. Three co-processing models that differ in how the workload is split among the CPU and GPU are introduced. Both routines are discussed and algorithms for executing them in parallel are presented. Experimental results for compressing a detail-rich UHD sequence to 4 bits/sample indicate speed-ups of 200x for the rate control and 100x for the packetization compared to the single-threaded implementation in the commercial Kakadu library. These two routines executed on the CPU take 4x as long as all remaining coding steps on the GPU and therefore present a bottleneck. Even if the CPU bottleneck could be avoided with multi-threading, it is still beneficial to execute all coding steps on the GPU as this minimizes the required device-to-host transfer and thereby speeds up the critical path from 17.2 fps to 19.5 fps for 4 bits/sample and to 22.4 fps for 0.16 bits/sample

Lyssna: a design fiction to reframe food waste

In this paper we propose the design fiction, Lyssna, a diegetic prototype in the form of a hearing aid for your refrigerator that aims at reintegrating lost aspects of food. Lyssna is based on home studies of food practices informed by Mediation Theory and Theories of Practice. Our aim is to explore an alternative framing from behavioral theories for designing for food waste. In the process, we hope to open up the design space for enabling reconfigurations of everyday food practices

Coaching practices in challenge-based learning:Characteristics in students' projects

Coaching students in CBL settings requires specific approaches. Although CBL has similar characteristics as Design-based learning (DBL), the educational concept and approach applied in the engineering programs at the Eindhoven University of Technology for over the past twenty years, CBL evolves from the DBL concept to emphasize the importance of addressing the sustainable development goals in education. Despite the fact that DBL coaching characteristics have been investigated, it becomes interesting to research these practices in CBL settings. The aim of this research study was to investigate coaching practices and explore differences among experienced coaches versus novice coaches, and the influence of the project set-up (e.g. group versus individual projects). The study was conducted in the department of Industrial Design, where students work on open- ended and hands-on challenges in groups or individually in the squad, an educational organizational form, where education and research come together. Project coaches and teacher coaches support the students to gain and apply knowledge and in the supervision of self-directed learning. The research method consisted of observations of coaching sessions (N=9), and semi-structured individual interviews with coaches (N=13 coaches) of various levels of experiences. Semistructured interviews with individual (N=14) and groups of students (N=3) took place. Data were analyzed using thematic analysis and categories within the framework of coaching in Design-based Learning by Gómez Puente (2013) and the theoretical framework of Cognitive Apprenticeship by Collins (1991). Results indicate that the 3 most frequently used coaching practices are a) asking open-ended questions; b) providing feedback on progress in technical design and design process; c) encouraging students to explore alternatives for problem solving using different perspectives. The results are in line with teaching the discipline as design process are embedded in uncertain and creative undertakings in which students are motivated to think big in proposing solutions. Novice coaches focused more on technical design while more experienced coaches encouraged students to reflect on their learning process and to become more self-regulated learners.</p

Context-awareness in task automation services by distributed event processing

Everybody has to coordinate several tasks everyday, usually in a manual manner. Recently, the concept of Task Automation Services has been introduced to automate and personalize the task coordination problem. Several user centered platforms and applications have arisen in the last years, that let their users configure their very own automations based on third party services. In this paper, we propose a new system architecture for Task Automation Services in a heterogeneous mobile, smart devices, and cloud services environment. Our architecture is based on the novel idea to employ distributed Complex Event Processing to implement innovative mixed execution profiles. The major advantage of the approach is its ability to incorporate context-awareness and real-time coordination in Task Automation Services

Feedforward Toaster: Design mapping for expressive use

This pictorial presents the design and design process of the Expressive Toaster, a research through design case that explores the mapping between the way the toaster is used and the way the bread is toasted. The Expressive Toaster is characterized by a textured cover that can be stroked to set the temperature as well as the duration of toasting. On the other hand, the texture enables the user to feel what the bread will become in terms of its crispiness. Some key insights taken from the iterative design process of the Expressive Toaster are elaborated in a visually annotated manner. With this work, we aim to provide practical design pointers for developing interaction mappings of expressive input to a delayed output over diverse modalities. We further intend to inspire design engineers to shift from function and menu based interfaces to expressive rich and other embodied mechanisms for interaction

Design for the Next: Integration of Path to Sustained Usage Model into Design Process

The aim of this chapter is to evaluate and further discuss the integration of the “Path to Sustained Usage” model into design process. To achieve this, this chapter explains the details and the outcomes of Engage! Workshop in which the model was tested with “backwards-designing” approach. The paper ends with further suggestions for application of the model into design process