Novel Methodologies for Predictable CPU-To-GPU Command Offloading

There is an increasing industrial and academic interest towards a more predictable characterization of real-time tasks on high-performance heterogeneous embedded platforms, where a host system offloads parallel workloads to an integrated accelerator, such as General Purpose-Graphic Processing Units (GP-GPUs). In this paper, we analyze an important aspect that has not yet been considered in the real-time literature, and that may significantly affect real-time performance if not properly treated, i.e., the time spent by the CPU for submitting GP-GPU operations. We will show that the impact of CPU-to-GPU kernel submissions may be indeed relevant for typical real-time workloads, and that it should be properly factored in when deriving an integrated schedulability analysis for the considered platforms. This is the case when an application is composed of many small and consecutive GPU compute/copy operations. While existing techniques mitigate this issue by batching kernel calls into a reduced number of persistent kernel invocations, in this work we present and evaluate three other approaches that are made possible by recently released versions of the NVIDIA CUDA GP-GPU API, and by Vulkan, a novel open standard GPU API that allows an improved control of GPU command submissions. We will show that this added control may significantly improve the application performance and predictability due to a substantial reduction in CPU-to-GPU driver interactions, making Vulkan an interesting candidate for becoming the state-of-the-art API for heterogeneous Real-Time systems. Our findings are evaluated on a latest generation NVIDIA Jetson AGX Xavier embedded board, executing typical workloads involving Deep Neural Networks of parameterized complexity

Factors affecting response of dogs to obedience instruction: a field and experimental study

Communication is an essential component of the translation of learning theory into the practical control of the behaviour of dogs. A handler sends a signal (e.g. a command), to which their dog responds. This response is dependent on the dog’s perception of the signal rather than the intention of the sender. Previous research has shown that a dog’s response can be influenced by specific changes in the verbal and non-verbal qualities of signals (i.e. the commands) used, but there has been little scientific evaluation of what happens in practice. Therefore in a first study, 56 dog handlers were videotaped giving their dogs a “sit” command and the significance of verbal and non-verbal factors on response was analyzed. Two factors were associated with a significant decrease in obedience: the dog’s attention to its handler and the handler giving additional verbal information preceding the actual verbal command. Based on these results, a second more controlled study was run with 12 dogs that were trained to a new (“uff”, i.e. jumping onto a raised surface) and a known (“sit”, “down” or “paw”) command. Once trained to predefined criteria, dogs were tested for their responsiveness with each of three additional types of verbal information preceding the command: the dog’s name, the dog’s name followed by a pause of 2 seconds and a “novel word”, i.e. a word with no established relationships in this context (“Banane”). The results suggest that the addition of the novel word significantly reduced response to both the known (p = 0.014) and the new (p = 0.014) commands. The name plus a pause preceding the command significantly reduced the response to the new command (p = 0.043), but not the known one. The use of the name before the command without a pause had no significant effect on performance. The dogs’ ability to generalize learned commands from the training context to a new context was tested by going through the same procedure in an unfamiliar environment. There was a significant reduction in correct responses only to the new command independent of the preceding verbal information (name (p = 0.028), name plus pause (p = 0.022) and novel word (p = 0.011)). This suggests that dogs may have more difficulties generalizing a less well-established command than an already known command

An in-flight investigation of pilot-induced oscillation suppression filters during the fighter approach and landing task

An investigation of pilot-induced oscillation suppression (PIOS) filters was performed using the USAF/Flight Dynamics Laboratory variable stability NT-33 aircraft, modified and operated by Calspan. This program examined the effects of PIOS filtering on the longitudinal flying qualities of fighter aircraft during the visual approach and landing task. Forty evaluations were flown to test the effects of different PIOS filters. Although detailed analyses were not undertaken, the results indicate that PIOS filtering can improve the flying qualities of an otherwise unacceptable aircraft configuration (Level 3 flying qualities). However, the ability of the filters to suppress pilot-induced oscillations appears to be dependent upon the aircraft configuration characteristics. Further, the data show that the filters can adversely affect landing flying qualities if improperly designed. The data provide an excellent foundation from which detail analyses can be performed

The Semantic Web Paradigm for a Real-Time Agent Control (Part II)

This paper is the second part of The Semantic Web Paradigm for a Real-time Agent Control, and the goal is to present the predictability of a multiagent system used in a learning process for a control problem (MASLCP).learning process, fuzzy control, agent predictability

The Relationship between Fuzzy Reasoning and Its Temporal Characteristics for Knowledge Management

The knowledge management systems based on artificial reasoning (KMAR) tries to provide computers the capabilities of performing various intelligent tasks for which their human users resort to their knowledge and collective intelligence. There is a need for incorporating aspects of time and imprecision into knowledge management systems, considering appropriate semantic foundations. The aim of this paper is to present the FRTES, a real-time fuzzy expert system, embedded in a knowledge management system. Our expert system is a special possibilistic expert system, developed in order to focus on fuzzy knowledge.Knowledge Management, Artificial Reasoning, predictability

Parallelism-Aware Memory Interference Delay Analysis for COTS Multicore Systems

In modern Commercial Off-The-Shelf (COTS) multicore systems, each core can generate many parallel memory requests at a time. The processing of these parallel requests in the DRAM controller greatly affects the memory interference delay experienced by running tasks on the platform. In this paper, we model a modern COTS multicore system which has a nonblocking last-level cache (LLC) and a DRAM controller that prioritizes reads over writes. To minimize interference, we focus on LLC and DRAM bank partitioned systems. Based on the model, we propose an analysis that computes a safe upper bound for the worst-case memory interference delay. We validated our analysis on a real COTS multicore platform with a set of carefully designed synthetic benchmarks as well as SPEC2006 benchmarks. Evaluation results show that our analysis is more accurately capture the worst-case memory interference delay and provides safer upper bounds compared to a recently proposed analysis which significantly under-estimate the delay.Comment: Technical Repor

Robot Swarms in an Uncertain World: Controllable Adaptability

There is a belief that complexity and chaos are essential for adaptability. But life deals with complexity every moment, without the chaos that engineers fear so, by invoking goal-directed behaviour. Goals can be programmed. That is why living organisms give us hope to achieve adaptability in robots. In this paper a method for the description of a goal-directed, or programmed, behaviour, interacting with uncertainty of environment, is described. We suggest reducing the structural (goals, intentions) and stochastic components (probability to realise the goal) of individual behaviour to random variables with nominal values to apply probabilistic approach. This allowed us to use a Normalized Entropy Index to detect the system state by estimating the contribution of each agent to the group behaviour. The number of possible group states is 27. We argue that adaptation has a limited number of possible paths between these 27 states. Paths and states can be programmed so that after adjustment to any particular case of task and conditions, adaptability will never involve chaos. We suggest the application of the model to operation of robots or other devices in remote and/or dangerous places.Comment: Journal web page & a lot of robotic related papers www.ars-journal.co

A piloted simulator investigation of stability and control, display and crew-loading requirements for helicopter instrument approach. Part 2: Supporting data

Pilot rating comments and standard deviation measures of flight performance and control use are presented

Theoretical Aspects of the Economic Transition: The Case of Romania

For Romania, as for all other ex-communist countries from Eastern Europe, the transition from the rigid centrally planned economic system to the free-market economy, fair competition based, was an amazing experience. From the academic standpoint, the economic reform was a huge research opportunity, as well as having extremely important practical consequences. Based on the case of Romania, the authors have developed an original, bi-dimensional matrix model of this transition process (Scarlat Model), emphasizing the typology of four basic economic systems. Managerial aspects are underlined – both for economic systems and transition process – as well as some stability considerations. Two features of the transition strategy are presented: the transition path and duration of the process. Special attention was paid to assessing the moment by when the economic transition ends. Analysis of the transition path – based on the theory of deterministic chaos (i.e. short-run predictability) – has led to interesting results: a comprehensive research on the evolution of the Romanian currency exchange over a period of sixteen years (1990–2005) revealed three intervals in the Romanian recent history of economic transition and confirmed the diagnostic of transition end. The general model is applied in the case of Romania and some interesting findings are presented, but it is also fully applicable to all Eastern European countries and not only Romania. The EU accessing process is a different type of transition – rigorously planned, regulated and monitored.economy model, economic transition, transition path, deterministic chaos, EU accession