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Alloy surface structure: computer simulations using the BFS method

SURFACE REVIEW AND LETTERS 1997年第5期4卷 825-828页

作者： Bozzolo, G Ferrante, J Analex Corp Brook Pk OH 44142 USA NASA Lewis Res Ctr Cleveland OH 44135 USA

The use of semiempirical methods for modeling ahoy properties has proven to be difficult and limited. The two primary approaches to this modeling, the embedded atom method and the phenomenological method of Miedema, have serious limitations in the range of materials studied and the degree of success in predicting properties of such systems. Recently, a new method has been developed by Bozzolo, Ferrante and Smith (BFS) which has had considerable success in predicting a wide range of alloy properties. In this work, we reference previous BFS applications to surface alloy formation and alloy surface structure, leading to the analysis of binary and ternary Ni-based alloy surfaces. We present Monte Carlo simulation results of thin films of NiAl and Ni-Al-Ti alloys, for a wide range of concentration of the Ti alloying addition. The composition of planes close to the surface as well as bulk features are discussed.

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Methodology for modeling visual flowchart control programs using net condition/event systems formalism in distributed environments

Methodology for modeling visual flowchart control programs u...

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international conference on Emerging Technologies and Factory Automation (ETFA)

作者： A. Lobov J.L.M. Lastra R. Tuokko V. Vyatkin Institute of Production Enginrering Tampere University of Technology Tampere Finland Department of Engineering Science Martin Luther University of Halle-Wittenberg Halle Germany

This paper addresses formal validation of distributed logic controllers represented in Visual Flowchart Language (VFL) that is a high-level programming language used in industrial automation. Traditional validation approaches based on simulation become obsolete in reconfigurable manufacturing systems where complex machines have decentralized control and are built by reuse of components. The source code based validation is also important for OEMs to unify their development procedures from embedded systems to machine controllers. For modeling the VFL design we used net condition/event systems (NCES) - a modular formalism developed for modeling systems with distributed states such as closed-loop control systems in distributed mechatronic devices. The methodology was implemented in software tools automatically generating the model's modules given the controller's source code. Then the hierarchical NCES model is assembled into a place/transition net that is subjected to model checking. The proposed approach facilitates integration of formal validation into software/hardware development in control systems' engineering.

关键词： Flowcharts Automatic control Distributed control Control systems Reconfigurable logic Logic programming computer languages Electrical equipment industry Industrial control Manufacturing industries

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“Fresh air”: The emerging landscape of design for networked embedded systems

“Fresh air”: The emerging landscape of design for networke...

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international conference on Hardware/Software Codesign and System Synthesis (CODES)

作者： Radu Marculescu Borivoje Nikolic Alberto-Sangiovanni Vincentelli Department of ECE Carnegie Mellon University Pittsburgh PA USA Department of EECS University of California Berkeley CA USA

As implementation architectures for complex systems evolve towards heterogeneous multiprocessing, let this be on a single chip or on a geographically distributed area, the importance of communication has reached unprecedented peaks. Indeed, due to the complex nature of interaction among its components, any complex system has behaviors that may be highly unpredictable. Dealing with such behaviors requires a deep understanding of various ways to enable communication and account for complex traffic patterns among different components of the system. So far, successful design of many integrated systems has been primarily based on algorithms and design methodologies meant to work under deterministic conditions where communication is considered in an ancillary role. However, in the light of emerging systems and applications (e.g. networked cars and buildings, smart surfaces and dense networks for health monitoring, and multi-core chips at nanoscale) this deterministic, computation-centered mindset no longer offers an appropriate approach. Indeed, such systems are highly distributed and heterogeneous, unreliable and redundant, so new approaches, distributed and stochastic in nature, need to be developed. Consequently, we need to move from a deterministic, computation-centered to a probabilistic, communication-based design paradigm to compensate for the lack of predictable behavior which used to be the norm in traditional systems. We need to consider optimization strategies that work in distributed collaborative networks and find new ways to model communication and traffic distributions in cars, buildings, or chips. Starting from these overarching ideas, this special session is meant to address the concept of probabilistic, communication-centric design in a variety of contexts and identify specific design principles and optimization techniques that are poised to redefine the landscape of system design in the near future. The first talk by A. Sangiovanni-Vincentelli addresses

关键词： embedded systems Buildings Optimization computer architecture Probabilistic logic Computational modeling USA Councils

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A distributed behavioral-based technique for multi-agent sensory & event-driven autonomous formation and navigation

A distributed behavioral-based technique for multi-agent sen...

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IEEE international Multi-Disciplinary conference on Cognitive Methods in Situation Awareness and Decision Support (CogSIMA)

作者： Dalila B. Megherbi Huthaifa Al-Omari CMINDS Research Center ECE Department University of Massachusetts Lowell USA

Many complex systems, such as multi-agent modeling and simulation which are crucial in military applications, necessitate concurrent task planning and decision making. These applications include battlefield modeling and simulation for soldier virtual training. In general these systems are implemented on automated systems with distributed architectures on heterogeneous operating systems and hardware platforms. In this paper we present an autonomous multi agent path planning system with agents-in-formation constraints in a distributed computing environment. Here a given agent, an entity with behaviors, exchanges sensory positioning feedback information over the network with other agents that are running on separate networked distributed computing nodes than the one the given agent is running on. Hence the agents do not have complete knowledge of the environment, but only a limited one. That is, in keeping with the agent formation constraint, the agents have knowledge only of the agents' information residing on the distributed memory of the computing node the agents are running on. The agents exchange agents' positioning sensory information of the rest of the agents they are interacting with, over a distributed network. Here agents autonomous trajectory planning is achieved for each agent to reach its destination via an unstructured distributed environment filled with dynamic obstacles and other agents. One focus is on the agents achieving their goals under real time formation constraints. We propose a multi-threaded architecture to achieve light-weight concurrency and multi-agent cooperative concurrency, as they allow separation between address space and thread control. Additionally, a threads-based architecture benefits from non-blocking system calls. Finally, experimental results are presented to show the potential of the proposed method for multi-agent distributed path planning.

关键词： computer architecture Message systems Distributed computing Message passing Multiagent systems Load management Navigation

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Model-Driven Performance Analysis of Reconfigurable Conveyor systems Used in Material Handling Applications

Model-Driven Performance Analysis of Reconfigurable Conveyor...

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IEEE/ACM international conference on Cyber-Physical systems (ICCPS)

作者： Kyoungho An Adam Trewyn Aniruddha Gokhale Shivakumar Sastry Department of Electrical Engineering and Computer Science Vanderbilt University Nashville TN USA Department of Electrical and Computer Engineering University of Akron Akron OH USA

Reconfigurable conveyors are increasingly being adopted in multiple industrial sectors for their immense flexibility in adapting to new products and product lines. Before modifying the layout of the conveyor system for the new product line, however, engineers and layout planners must be able to answer many questions about the system, such as maximum sustainable rate of flow of goods, prioritization among goods, and tolerances of failures. Any analysis capability that provides answers to these questions must account for both the physical and cyber artifacts of the reconfigurable system all at once. Moreover, the same system should enable the stakeholders to seamlessly change the layouts and be able to analyze the pros and cons of the layouts. This paper addresses these challenges by presenting a model-driven analysis tool that provides three important capabilities. First, a domain-specific modeling language provides the stakeholders with intuitive artifacts to model conveyor layouts. Second, an analysis engine embedded within the model-driven tool provides an accurate simulation of the modeled conveyor system accounting for both the physical and cyber issues. Third, generative capabilities within the tool help to automate the analysis process. The merits of our model-driven analysis tool are evaluated in the context of an example conveyor topology.

关键词： Analytical models Mathematical model Layout Manufacturing systems Materials Engines Sensors

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GCMR: A GPU Cluster-Based MapReduce Framework for Large-Scale Data Processing

GCMR: A GPU Cluster-Based MapReduce Framework for Large-Scal...

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IEEE international conference on High Performance Computing and Communications (HPCC)

作者： Yiru Guo Weiguo Liu Bin Gong Gerrit Voss Wolfgang Muller-Wittig Sch. of Comput. Sci. & Technol. Shandong Univ. Jinan China Fraunhofer IDM@NTU Nanyang Technol. Univ. Singapore Singapore

MapReduce is a very popular programming model to support parallel and distributed large-scale data processing. There have been a lot of efforts to implement this model on commodity GPU-based systems. However, most of these implementations can only work on a single GPU. And they can not be used to process large-scale datasets. In this paper, we present a new approach to design the MapReduce framework on GPU clusters for handling large-scale data processing. We have used Compute Unified Device architectures (CUDA) and MPI parallel programming models to implement this framework. To derive an efficient mapping onto GPU clusters, we introduce a two-level parallelization approach: the inter node level and intra node level parallelization. Furthermore in order to improve the overall MapReduce efficiency, a multi-threading scheme is used to overlap the communication and computation on a multi-GPU node. Compared to previous GPU-based MapReduce implementations, our implementation, called GCMR, achieves speedups up to 2.6 on a single node and up to 9.1 on 4 nodes of a Tesla S1060 quad-GPU cluster system for processing small datasets. It also shows very good scalability for processing large-scale datasets on the cluster system.

关键词： Graphics processing units Instruction sets Computational modeling computer architecture Acceleration Writing Data processing

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BIBNet: An Efficient Super Resolution with Bottleneck-In-Bottleneck

BIBNet: An Efficient Super Resolution with Bottleneck-In-Bot...

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international Joint conference on Neural Networks (IJCNN)

作者： Simyung Chang Keuntek Lee Shobhit Jain Cheul-hee Hahm Visual Display Division Samsung Electronics Suwon Korea

ISBN: (数字)9781728169262

ISBN: (纸本)9781728169279

Deep Neural Networks have enabled remarkable progress in the field of single image super resolution (SR). However, these models are often large and complex to be applied for real-world applications with limited resources as in mobile and embedded systems. We investigate whether the typical low latency models as MobileNet can be expected of comparable efficiency at SR tasks with recently reported SR performance in the literature. To this end, a moderate and effective architecture, Bottleneck-In-Bottleneck (BIB), is introduced in this paper. The BIB uses multiple expansion factors of the residual blocks in the form of a bottleneck, reducing computation complexity while utilizing advantageous factors of large feature dimensions. We also propose BIBNet with multiple BIB blocks, which can easily adjust its size and computational cost to create a variety of efficient and high-performance models. Extensive experiments show that, with fewer parameters and computations, BIBNet achieves highly competitive performance compared to other conventional SR methods with more complex architectures.

关键词： Convolution Computational modeling Image resolution computer architecture Task analysis Computational efficiency Machine learning

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Preface

Proceedings - 2016 16th International Conference on Embedded...

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Proceedings - 2016 16th international conference on embedded computer systems: architectures, modeling and simulation, SAMOS 2016 2016年

作者： Gerstlauer, Andreas Najjar, Walid

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Controlling hopping height of a pneumatic monopod

Controlling hopping height of a pneumatic monopod

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IEEE international conference on Robotics and Automation (ICRA)

作者： K. Harbick G.S. Sukhatme Robotics Research Laboratories Department of Computer ScienceRobotic Embedded Systems Laboratory University of Southern California Los Angeles CA USA

We describe a model-based height controller for a hopping robot with a pneumatically powered leg. The controller explicitly models variation in the leg angle and height. Using an explicit model of the physics of the pneumatic spring and some symmetry assumptions, we derive the desired leg-length setting to regulate apex hopping height using a PD controller. simulation experiments of hopping in the sagittal plane show reasonable height regulation. For low-speed running, we take advantage of the small variations in the leg angle about the vertical, and demonstrate that the original symmetry assumptions may be relaxed by restricting the leg angle to /spl pi//2. simulations show that the restricted model outperforms the original model by a small but significant amount.

关键词： Leg Springs Velocity control Legged locomotion Power system modeling Control systems Laboratories Physics Navigation Foot

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State estimation of an autonomous helicopter using Kalman filtering

State estimation of an autonomous helicopter using Kalman fi...

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Proceedings 1999 IEEE/RSJ international conference on Intelligent Robots and systems. Human and Environment Friendly Robots with High Intelligence and Emotional Quotients (Cat. No.99CH36289)

作者： Myungsoo Jun S.I. Roumeliotis G.S. Sukhatme Department of Electrical Engineering-Systems USA Department of Computer Science Institute for Robotics and Intelligent Systems University of Southern California Los Angeles CA USA

Presents a technique to accurately estimate the state of a robot helicopter using a combination of gyroscopes, accelerometers, inclinometers and GPS. simulation results of state estimation of the helicopter are presented using Kalman filtering based on sensor modeling. The number of estimated states of helicopter is nine : three attitudes(/spl theta/,/spl phi/,/spl psi/) from the gyroscopes, three accelerations(x/spl ***/,y/spl ***/,z/spl ***/) and three positions (x, y, z) from the accelerometers. Two Kalman filters were used, one for the gyroscope data and the other for the accelerometer data. Our approach is unique because it explicitly avoids dynamic modeling of the system and allows for can elegant combination of sensor data available at different frequencies. We also describe the larger context in which this work is embedded, namely the design and implementation of an autonomous robot helicopter.

关键词： State estimation Helicopters Kalman filters Gyroscopes Accelerometers Filtering Robot sensing systems Global Positioning System Acceleration Sensor systems

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