Supplementing Frequency Domain Interpolation Methods for Character Animation

The animation of human characters entails difficulties exceeding those met simulating objects, machines or plants. A person's gait is a product of nature affected by mood and physical condition. Small deviations from natural movement are perceived with ease by an unforgiving audience. Motion capture technology is frequently employed to record human movement. Subsequent playback on a skeleton underlying the character being animated conveys many of the subtleties of the original motion. Played-back recordings are of limited value, however, when integration in a virtual environment requires movements beyond those in the motion library, creating a need for the synthesis of new motion from pre-recorded sequences. An existing approach involves interpolation between motions in the frequency domain, with a blending space defined by a triangle network whose vertices represent input motions. It is this branch of character animation which is supplemented by the methods presented in this thesis, with work undertaken in three distinct areas. The first is a streamlined approach to previous work. It provides benefits including an efficiency gain in certain contexts, and a very different perspective on triangle network construction in which they become adjustable and intuitive user-interface devices with an increased flexibility allowing a greater range of motions to be blended than was possible with previous networks. Interpolation-based synthesis can never exhibit the same motion variety as can animation methods based on the playback of rearranged frame sequences. Limitations such as this were addressed by the second phase of work, with the creation of hybrid networks. These novel structures use properties of frequency domain triangle blending networks to seamlessly integrate playback-based animation within them. The third area focussed on was distortion found in both frequency- and time-domain blending. A new technique, single-source harmonic switching, was devised which greatly reduces it, and adds to the benefits of blending in the frequency domain

Desztilláció modellezésére alkalmas új korrelációs függvények azeotróp elegyek gőz-folyadék egyensúlyi görbéire: New correlation functions of VLE-curves of azeotropic mixtures for distillation modelling purposes

The simulation of distillation processes require accurate vapour-liquid equilibrium (VLE) data, since even minor (few percent) of deviation of them could cause major differences between the model results and the real system behavior. The azeotropic mixtures are highly non-ideal systems, displaying exotic phase behavior, as inflection points, which create difficulties in fitting attempts. The VLE data are available in general as discrete values, but for modeling and design of the separation processes, continuous function would be more practical. We developed a simple method to identify several function types for fitting on VLE data for whole concentration domain. The results are empirical, as do not imply thermodynamic considerations. The fitting parameters of binary ethanol-water mixture VLE curve were determined, and give the lowest relative error, compared with the results from the literature data. The best fitted function was suitable for calculation of tray number of distillation column with McCabe-Thiele method, implementing them in an Excel spreadsheet, giving similar result with Vaxa McCabe-Thiele software. The methodology is suitable for fitting continuous functions on VLE data for non-ideal binary or multi-component mixtures both. Kivonat A desztillációs folyamatok szimulációja pontos gőz-folyadék egyensúlyi adatokat igényel, mivel ezek kismértékű (néhány százalékos) eltérése jelentős eltéréseket okozhat a modell eredményei és a rendszer valós viselkedése között. Az azeotróp keverékek fokozottan nem-ideális rendszerek, amelyek különös viselkedést mutatnak pl. áthajlási ponttal rendelkeznek, ami nehézségeket okoz az illesztési megvalósításában. Az egyensúlyi adatok általában diszkrét értékekként állnak rendelkezésre, de az elválasztási folyamatok modellezéséhez és tervezéséhez a folyamatos görbék célszerűbbek. Egyszerű módszert dolgoztunk ki függvénytípusok azonosítására, melyek az egyensúlyi görbe teljes koncentráció-tartományában illeszkednek. Az eredmények empirikusak, mivel nem alkalmaztuk  termodinamikai meggondolásokat. Meghatároztuk a bináris etanol-víz keverék egyensúlyi görbéjének illeszkedési paramétereit, amelyek az irodalmi adatok eredményeivel összehasonlítva a legalacsonyabb relatív hibát adták. A legjobban illeszkedő függvény alkalmas volt a desztillációs oszlop tányérszámának McCabe-Thiele módszerrel történő kiszámítására, Excel táblázattal, hasonló eredményt adva a Vaxa McCabe-Thiele szoftvere. A módszer alkalmas folytonos egyensúlyi függvények illesztésére, nem-ideális bináris vagy többkomponensű keverékek esetére is

Building Faithful High-level Models and Performance Evaluation of Manycore Embedded Systems

International audiencePerformance and functional correctness are key for successful design of modern embedded systems. Both aspects must be considered early in the design process to enable founded decision making towards final implementation. Nonetheless, building abstract system-level models that faithfully capture performance information along to functional behavior is a challenging task. In contrast to functional aspects, performance details are rarely available during early design phases and no clear method is known to characterize them. Moreover, once such system-level models are built they are inherently complex as they usually mix software models, hardware architecture constraints and environment abstractions. Their analysis by using traditional performance evaluation methods is reaching the limits and the need for more scalable and accurate techniques is becoming urgent. In this paper, we introduce a systematic method for building stochastic abstract performance models using statistical inference and model calibration and we propose statistical model checking as performance evaluation technique upon the obtained models. We experimented our method on a real-life case study. We were able to verify different timing properties

Composability and Predictability for Independent Application Development, Verification and Execution

System-on-chip (SOC) design gets increasingly complex, as a growing number of applications are integrated in modern systems. Some of these applications have real-time requirements, such as a minimum throughput or a maximum latency. To reduce cost, system resources are shared between applications, making their timing behavior inter-dependent. Real-time requirements must hence be verified for all possible combinations of concurrently executing applications, which is not feasible with commonly used simulation-based techniques. This chapter addresses this problem using two complexity-reducing concepts: composability and predictability. Applications in a composable system are completely isolated and cannot affect each other’s behaviors, enabling them to be independently verified. Predictable systems, on the other hand, provide lower bounds on performance, allowing applications to be verified using formal performance analysis. Five techniques to achieve composability and/or predictability in SOC resources are presented and we explain their implementation for processors, interconnect, and memories in our platform

A composable, energy-managed, real-time MPSOC platform.

Multi-processors systems on chip (MPSOC) platforms emerged in embedded systems as hardware solutions to support the continuously increasing functionality and performance demands in this domain. Such a platform has to execute a mix of applications with diverse performance and timing constraints, i.e., real-time or non-real-time, thus different application schedulers should co-exist on an MPSOC. Moreover, applications share many MPSOC resources, thus their timing depends on the arbitration at these resources. Arbitration may create inter-application dependencies, e.g., the timing of a low priority application depends on the timing of all higher priority ones. Application inter-dependencies make the functional and timing verification and the integration process harder. This is especially problematic for real-time applications, for which fulfilling the time-related constraints should be guaranteed by construction. Moreover, energy and power management, commonly employed in embedded systems, make this verification even more difficult. Typically, energy and power management involves scaling the resources operating point, which has a direct impact on the resource performance, thus influences the application time behaviour. Finally, a small change in one application leads to the need to re-verify all other applications, incurring a large effort. Composability is a property meant to ease the verification and integration process. A system is composable if the functionality and the timing behaviour of each application is independent of other applications mapped on the same platform. Composability is achieved by utilising arbiters that ensure applications independence. In this paper we present the concepts behind a composable, scalable, energy-managed MPSOC platform, able to support different real-time and nonreal time schedulers concurrently, and discuss its advantages and limitations

Energy Management via PI Control for Data Parallel Applications with Throughput Constraints

International audienceThis paper presents a new proportional-integral (PI) controller that sets the operating point of computing tiles in a system on chip (SoC). We address data-parallel applications with throughput constraints. The controller settings are investigated for application configurations with different QoS levels and different buffer sizes. The control method is evaluated on a test chip with four tiles executing a realistic HMAX object recognition application. Experimental results suggest that the proposed controller outperforms the state-of-the-art results: it attains, on average, 25% less number of frequency switches and has slightly higher energy savings. The reduction in number of frequency switches is important because it decreases the involved overhead. In addition, the PI controller meets the throughput constraint in cases where other approaches fail

Composable local memory organisation for streaming applications on embedded MPSoCs

Multi-Processor Systems on a Chip (MPSoCs) are suitable platforms for the implementation of complex embedded applications. An MPSoC is composable if the functional and temporal behaviour of each application is independent of the absence or presence of other applications. Composability is required for application design and analysis in isolation, and integration with linear effort. In this paper we propose a composable organisation for the top level of a memory hierarchy. This organisation preserves the short (one cycle) access time desirable for a processor's frequent local accesses and enables the predictability demanded by real-time applications. We partition the local memory in two blocks, one private, for local tile data, and another shared for inter-tile data communication. To avoid application interference, we instantiate one such shared local memory block and an Remote Direct Memory Access (RDMA) for each application running on the processor. We implement this organisation on an MPSoC with two processors on an FPGA. On this platform we execute a composition of applications consisting of a JPEG decoder, and a synthetic application. Our experiments indicate that an application's timing is not affected by the behaviour of another application, thus composability is achieved. Moreover, the utilisation of the RDMA component leads to 45% performance increase on average for a number of workloads covering a large range of communication/computation ratios