Partitioned global address space (PGAS) applications, such as the Tensor Contraction Engine (TCE) in NWChem, often apply a one-process-per-core mapping in which each process iterates through the following work-process...
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ISBN:
(纸本)9781479976164
Partitioned global address space (PGAS) applications, such as the Tensor Contraction Engine (TCE) in NWChem, often apply a one-process-per-core mapping in which each process iterates through the following work-processing cycle: (1) determine a work-item dynamically, (2) get data via one-sided operations on remote blocks, (3) perform computation on the data locally, (4) put (or accumulate) resultant data into an appropriate remote location, and (5) repeat the cycle. However, this simple flow of execution does not effectively hide communication latency costs despite the opportunities for making asynchronous progress. Utilizing nonblocking communication calls is not sufficient unless care is taken to efficiently manage a responsive queue of outstanding communication requests. This paper presents a new runtime model and its library implementation for managing tunable “work queues” in PGAS applications. Our runtime execution model, called WorkQ, assigns some number of on-node “producer” processes to primarily do communication (steps 1, 2, 4, and 5) and the other “consumer” processes to do computation (step 3); but processes can switch roles dynamically for the sake of performance. Load balance, synchronization, and overlap of communication and computation are facilitated by a tunable nodewise FIFO message queue protocol. Our WorkQ library implementation enables an MPI+X hybrid programming model where the X comprises SysV message queues and the user's choice of SysV, POSIX, and MPI shared memory. We develop a simplified software mini-application that mimics the performance behavior of the TCE at arbitrary scale, and we show that the WorkQ engine outperforms the original model by about a factor of 2. We also show performance improvement in the TCE coupled cluster module of NWChem.
In this paper,we consider the problem of designing traffic network signal control systems for congested urban road networks,aiming to relieve traffic congestion and improve the utilization of the existing traffic infr...
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In this paper,we consider the problem of designing traffic network signal control systems for congested urban road networks,aiming to relieve traffic congestion and improve the utilization of the existing traffic infrastructures.A Model Predictive Control(MPC)method is introduced which is based on a microscopic store-and-forward modeling(SFM)***,a preliminary simulation of urban traffic flow management is implemented with the help of MATLAB/SIMULINK and *** results demonstrate the efficiency and feasibility of the MPC signal control method,which can take all the operational constraints into consideration *** the MPC control framework can also be applied for other infrastructure systems whose characteristics are common intelligent,from a generic point of view.
The vehicular real-time broadcast is realized on the foundation of train-ground wireless communication of passenger information system of urban rail transit,which has been implied *** order to realize the WLAN service...
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The vehicular real-time broadcast is realized on the foundation of train-ground wireless communication of passenger information system of urban rail transit,which has been implied *** order to realize the WLAN service with high bandwidth and high quality and enable the performance of WLAN to reach that of Ethernet,802.11n was born,which adopts frequency channel of 2.4GHz and 5GHz,takes MIMO(multiple-input multiple-output) and OFDM as its key technologies,transmits data at rate of 300Mbps up to 600Mbps,has downward compatibility with application research on 802.11b and *** paper proposes application research and put forward implementation suggestions with simulation test,provides reference for the future applications of PIS of urban rail transit,planning and selection of wireless communication.
There has been extensive research on active safety systems in the ITS community in recent years that has significantly contributed to reducing traffic ***,further reduction is needed,especially on residential roads,wh...
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There has been extensive research on active safety systems in the ITS community in recent years that has significantly contributed to reducing traffic ***,further reduction is needed,especially on residential roads,where the reduction rate of traffic accidents is still quite *** residential roads,traffic accidents are caused primarily by pedestrians suddenly running in front of cars and by the inattention of drivers to such *** emergency braking systems activated by pedestrian detection are not always reliable on residential roads due to physical limitations such as too short a braking *** overcome the limitations of current active safety management systems,we focus on risk anticipation and defensive driving,key ideas to ensure safety on residential *** defensive driving requires careful deceleration in advance of barrier lines and the corners of streets,long-term driver behavior prediction is *** this work,we provide a new framework of modeling risk anticipation and defensive driving with inverse reinforcement learning(IRL).In contrast to conventional driver behavior models such as hidden Markov models and maximum-entropy Markov models,our framework using IRL ensures accurate long-term prediction of driver maneuvers since the IRL is based on the Markov decision process(MDP),a goal-oriented path planning *** the predicted defensive driver behaviors obtained by an MDP are appropriate only when the reward functions are carefully designed,we use inverse reinforcement learning,where the normative behavior of expert drivers is leveraged to optimize the reward *** addition to the proposed formulation of defensive driving with IRL,we provide new feature descriptors for computing reward functions to represent risk factors on residential roads such as corners,barrier lines,and speed *** results using actual driver maneuver data over 20 km of residential roads indicate that our ap
Rodents as widespread pests cause significant damages to the crops, stored foods, human being and properties. For rodent's control there has been no systematic high-tech solution so far. We aim to raise this probl...
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This paper presents a work in progress for a proposed method for Content Based Image Retrieval (CBIR) and Classification. The proposed method makes use of the interest points detector and descriptor called Speeded-Up ...
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SOA brought significant progress in information systems development, but the full exploitation of its advantages is sometimes hindered by specific problems. One of them is concerned with paradigm of Model Driven Devel...
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Rodents as widespread pests cause significant damages to the crops, stored foods, human being and properties. For rodent's control there has been no systematic high-tech solution so far. We aim to raise this probl...
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ISBN:
(纸本)9781479906314
Rodents as widespread pests cause significant damages to the crops, stored foods, human being and properties. For rodent's control there has been no systematic high-tech solution so far. We aim to raise this problem as a new challenging and multidisciplinary research area. We will propose our solution based on cyber-physical systems (CPSs) and will elucidate enabling technologies and frontiers for this research.
SOA brought significant progress in information systems development, but the full exploitation of its advantages is sometimes hindered by specific problems. One of them is concerned with paradigm of Model Driven Devel...
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SOA brought significant progress in information systems development, but the full exploitation of its advantages is sometimes hindered by specific problems. One of them is concerned with paradigm of Model Driven Development (MDD), where it is necessary to control correctness of the whole design within many models on different levels of abstraction. This is the place, where we would like to contribute. We propose a new approach to application of SOA design patterns in the development process. Patterns are transformed into a machine acceptable form using category theory and attributed graphs. This form is language independent, leads up to automated detection of pattern or antipattern in the description/model of SOA based system and in the future can facilitate also correctness checking.
Resource allocation is an active direction of research that is drawing interest within academic and technological circles. Resource allocation imposes numerous challenges. This is especially true for Inter-Clouds, a r...
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Resource allocation is an active direction of research that is drawing interest within academic and technological circles. Resource allocation imposes numerous challenges. This is especially true for Inter-Clouds, a recent paradigm for horizontal expansion and integration of disparate and heterogeneous cloud platforms. In an attempt to realize an efficient resource management system, this work-in-progress paper proposes and describes a new multi-layered management framework to address the tasks of virtualized resource control, dynamic resource provisioning, life-cycle management and resource exchange within Inter-Cloud environments.
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