Among the various isolated inverter topologies for grid connection of the renewable energies, the differentialmode Ćuk inverter has several outstanding features. It has lower number of devices, which are low-side driv...
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Among the various isolated inverter topologies for grid connection of the renewable energies, the differentialmode Ćuk inverter has several outstanding features. It has lower number of devices, which are low-side driven. It has lower high-frequency ripple on the both ac and dc sides. This paper introduces a new modulation technique intended to eliminate the power circulation by manipulating just one module at a time which leads to a better efficiency.
This work intends to schedule a dual-arm cluster tool for the atomic layer deposition (ALD) process with wafer residency time constraints. ALD is a typical wafer revisiting process. Based on the analysis of system pro...
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Virtual machine placement is a process of mapping virtual machines to physical machines. The optimal placement is important for improving power efficiency and resource utilization in a cloud computing environment. In ...
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With the growing demand in high performance computing , reconfigurable computingsystems built with Field Programmable Gate Array (FPGA) have become increasingly popular for its reconfigurability and adaptability to a...
With the growing demand in high performance computing , reconfigurable computingsystems built with Field Programmable Gate Array (FPGA) have become increasingly popular for its reconfigurability and adaptability to applications. Although such systems promise high processing performance, their energy efficiency has become a critical issue. This paper studies the crucial problem of energy-efficient scheduling for reconfigurable systems with multiple FPGAs. Several factors make the energy efficient scheduling particularly challenging, including spatial allocation constraint, reconfiguration overhead, limited reconfiguration ports, and deadline satisfaction. These unique characteristics make energy efficient scheduling in multi-FPGA reconfigurable systems particularly challenging and none of existing solutions can be directly applied. This paper takes on this challenge and proposes an energy-efficient scheduling algorithm called AEE based on ant colony optimization for multi-FPGA reconfigurable systems. A task placement scheme is devised which serves as the heuristic function that derives the minimum global makespan, which is important to the ant colony algorithm based proposed in the paper . The scheme takes into account reconfiguration overhead and places tasks for reducing the overall overhead. Then, based on AEE, an enhanced algorithm (eAEE) is devised to deal with the tasks with precedence and interdependencies . To evaluate the effectiveness of the two proposed algorithms, comprehensive trace-driven simulations have been conducted and compared with other state-of-art algorithms. Experimental results demonstrate that AEE can successfully complete tasks without violating deadline constraints and the energy dissipation is largely reduced, no more than 10.65% higher than the optimum when the problem scale is relatively small. Also, eAEE consumes energy 58.17% less than an improved simulated annealing algorithm (iSA) with a large problem scale .
The experimental trajectory control of a Tri-TiltRotor Unmanned Aerial Vehicle in rotorcraft hovering operation is the subject of this paper. This reconfigurable UAV is designed for autonomous conversion between the V...
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ISBN:
(纸本)9781479909964
The experimental trajectory control of a Tri-TiltRotor Unmanned Aerial Vehicle in rotorcraft hovering operation is the subject of this paper. This reconfigurable UAV is designed for autonomous conversion between the Vertical TakeOff and Landing, and the Fixed-Wing flight modes. Via employing the additional control authority gained by rotor-tilting, the full actuation of the UAV longitudinal dynamics is achieved. Based on this novel feature, longitudinal thrust vectoring of the main rotors is performed, and the respective degree-of-freedom is significantly benefited while performing rotorcraft hovering flight. The system custom autopilot is based on a Proportional Integral-Derivative-double Derivative scheme, exploiting the augmented UAV state vector for control, while the custom-developed sensor suite and state estimation system provides fully autonomous operation. Extensive experimental studies validate the control scheme's efficiency, while remarking the advantageous effects of the longitudinal thrust vectoring-based control authority.
Multimedia SIMD extensions are commonly employed today to speed up media processing. When performing vectorization for SIMD architectures, one of the major issues is to handle the problem of memory alignment. Prior st...
Multimedia SIMD extensions are commonly employed today to speed up media processing. When performing vectorization for SIMD architectures, one of the major issues is to handle the problem of memory alignment. Prior study focused on either vectorizing loops with all memory references being properly aligned, or introducing extra operations to deal with the misaligned memory references. On the other hand, multi-core SIMD architectures require coarse-grain parallelism. Therefore, it is an important problem to study how to parallelize and vectorize loop nests with the awareness of data misalignments. This paper presents a loop transformation scheme that maximizes the parallelism of outermost loops, while the misaligned memory references in innermost loops are reduced. The basic idea of our technique is to align each level of loops in the nest, considering the constraint of dependence relations. To reduce the data misalignments, we establish a mathematical model with a concept of offset-collection and propose an effective heuristic algorithm. For coarser-grain parallelism, we propose some rules to analyze the outermost loop. When transformations are applied, the inner loops are involved to maximize the parallelism. To avoid introducing more data misalignments, the involved innermost loop is handled from other levels of loops. Experimental results show that 7 % to 37 % (on average 18.4 %) misaligned memory references can be reduced. The simulations on CELL show that 1.1x speedup can be reached by reducing the misaligned data, while 6.14x speedup can be achieved by enhancing the parallelism for multi-core.
The experimental translational hovering control of a Tri-TiltRotor Unmanned Aerial Vehicle is the subject of this paper. This novel UAV is developed to possess the capability to perform autonomous conversion between t...
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ISBN:
(纸本)9781467356404
The experimental translational hovering control of a Tri-TiltRotor Unmanned Aerial Vehicle is the subject of this paper. This novel UAV is developed to possess the capability to perform autonomous conversion between the Vertical Take-Off and Landing, and the Fixed-Wing flight modes. Via this design's implemented features however, the capability for additional control authority on the UAV's longitudinal translational motion arises: The rotor-tilting servos are utilized in performing thrust vectoring of the main rotors, thus exploiting their fast response characteristics in directly providing translation-controlling forces. The system's hovering translation is handled by a Model Predictive Control scheme, following the aforementioned actuation principles. While performing experimental studies of the overall controlled system's efficiency, the advantageous effects of this novel control authority are clearly noted. Additionally, in this article the considerations and requirements for operational autonomy-related on-board-only state estimation are addressed.
It is very challenging to schedule a multi-cluster tool for it needs to coordinate the activities of multiple robots. This paper studies one-wafer cyclic scheduling for multi-cluster tools whose bottleneck cluster too...
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This article was originally published online on 27 November 2013. Due to a production error, a subscript was omitted from one of the terms in Eq. (3). AIP Publi
This article was originally published online on 27 November 2013. Due to a production error, a subscript was omitted from one of the terms in Eq. (3). AIP Publi
This paper is concerned with the H ∞ filtering for networked systems with multiple time-varying transmissions and random packet dropouts. We design a remote H ∞ filter for these two networked issues such that the ...
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This paper is concerned with the H ∞ filtering for networked systems with multiple time-varying transmissions and random packet dropouts. We design a remote H ∞ filter for these two networked issues such that the filtering error system is exponentially stable and achieves a prescribed H ∞ performance level. A switched system approach is used to model the multiple time-varying transmission process, and a set of stochastic variables are employed to describe the random packet dropout phenomenon. By the switched system theory and some stochastic analysis methods, a sufficient condition for the existence of the H ∞ filter is derived in terms of linear matrix inequalities (LMIs). Moreover, the filter gains are determined by solving an optimization problem. Two numerical examples are given to illustrate the effectiveness of the proposed design method.
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