Integrated with low-power micro-controllers and sensors, RFID-based wireless rechargeable sensor node is a very promising platform for applications such as inventory management, supply chain monitoring etc. Among othe...
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Integrated with low-power micro-controllers and sensors, RFID-based wireless rechargeable sensor node is a very promising platform for applications such as inventory management, supply chain monitoring etc. Among other major research challenges, one of the most essential problems in such wireless rechargeable sensor networks is how to minimize the communication delay among RFID readers and RFID-based rechargeable nodes. While the existing works have mostly focused on the collision avoidance among RFID-based nodes, in this work we study an orthogonal approach which focuses on how to optimally plan the movement of the reader so as to minimize the communication delay in the network. To solve this problem, we introduce both an optimal solution for the linear reader movement pattern and an approximation solution for the generic two-dimensional reader move pattern with a provable approximation ratio. In addition, we also provide a solution for guaranteeing the quality of communication while minimizing the communication delay. We verify our observations through testbed experiments and extensively evaluate our design by both emulations and large-scale simulations. The results show our design can effectively reduce communication delay in wireless rechargeable sensor networks when compared with baseline solutions.
With the constant expansion of power grid, a large number of security constraints have put tremendous challenges to the online economic dispatch. An efficient tool to eliminate the inactive constraints becomes necessa...
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High Voltage Direct Current (HVDC) lines allow large quantities of power to be transferred between two points in an electrical power system. A Multi-Terminal HVDC (MTDC) grid consists of a meshed network of HVDC lines...
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High Voltage Direct Current (HVDC) lines allow large quantities of power to be transferred between two points in an electrical power system. A Multi-Terminal HVDC (MTDC) grid consists of a meshed network of HVDC lines, and this allows energy reserves to be shared between a number of AC areas in an efficient manner. Secondary Frequency control (SFC) algorithms return the frequencies in areas connected by AC or DC lines to their original setpoints after Primary Frequency controllers have been called following a contingency. Where multiple TSOs are responsible for different parts of a MTDC grid it may not be possible to implement SFC from a centralised location. Thus, in this paper a simple gain based distributed Model Predictive control strategy is proposed for Secondary Frequency control of MTDC grids which allows TSOs to cooperatively perform SFC without the need for centralised coordination.
Nowadays parallel manipulators are used widely in bioengineering applications; this leads to many exciting expectations as well as challenges. The kinematic analysis of parallel manipulators with their differential ki...
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Nowadays parallel manipulators are used widely in bioengineering applications; this leads to many exciting expectations as well as challenges. The kinematic analysis of parallel manipulators with their differential kinematics yielding the Jacobian in a closed form is not a trivial task. In this paper a parallel manipulator based mobility assistive device called EJADII is analyzed to determine forward kinematics, inverse kinematics and closed-form Jacobian. An Adaptive Neuro-Fuzzy Inference System (ANFIS) is trained to estimate the Jacobian. This system would be useful when determination of the Jacobian in a closed-form is difficult to determine. The human motion during sit to stand captured by VICON experiment is used with two assisting scenarios to train and verify this system. computer simulations show relatively good results of the proposed system.
A novel on-line diagnosis method is proposed in this paper that uses a qualitative dynamic model of the system and its colored Petri nets model. The model contains both the normal and the possible faulty operational m...
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ISBN:
(纸本)9789077381861
A novel on-line diagnosis method is proposed in this paper that uses a qualitative dynamic model of the system and its colored Petri nets model. The model contains both the normal and the possible faulty operational modes of the system. The deviation between the normal and faulty modes is characterized based on P-HAZID tables. The actual system state can be searched on the occurrence graph constructed in advance. Starting from this node the possible consequences and root causes can be determined on-line with traversing on the graph. The proposed method is illustrated on simple case studies.
A novel fault integration method is proposed in this paper for manufacturing system models given in the form of timed colored Petri nets. The faults are assumed to have a stochastic nature and are represented in the f...
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ISBN:
(纸本)9789077381861
A novel fault integration method is proposed in this paper for manufacturing system models given in the form of timed colored Petri nets. The faults are assumed to have a stochastic nature and are represented in the form of transitions firing in stochastic way with known fault probabilities in the system model. A novel fault effect propagation method was also developed, that can be used to compute the probabilities of the possible faulty and non-faulty intermediate and final states of the system using the probabilities of faults and the occurrence graph. The faultless and fault containing models were implemented in CPNTools both for non-timed and timed cases. A software module was also developed for the proposed probabilistic fault propagation analysis. The proposed methods and tools were demonstrated using a simple case study.
Clustering analysis is an important tool of data mining. The study on efficient clustering has great significance, especially in improving a clustering algorithm's adaptability and usefulness. Clustering ensemble ...
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Clustering analysis is an important tool of data mining. The study on efficient clustering has great significance, especially in improving a clustering algorithm's adaptability and usefulness. Clustering ensemble (CE) integrates several clustering algorithms such that the clustering results can be effectively improved. This work investigates similarity-based methods and proposes a new method called weight- incorporated similarity-based clustering ensemble (WSCE). Six classic data sets are used to test single clustering algorithms, similarity-based one, and the proposed one via simulation. The results prove the validity and performance advantage of the proposed method.
Context: the presence of several languages interacting each other within the same project is an almost universal feature in software development. Earlier work shows that this interaction might be source of problems. O...
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Active fault isolation of parametric faults in closed-loop MIMO systems are considered in this paper. The fault isolation consists of two steps. The first step is group-wise fault isolation. Here, a group of faults is...
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Active fault isolation of parametric faults in closed-loop MIMO systems are considered in this paper. The fault isolation consists of two steps. The first step is group-wise fault isolation. Here, a group of faults is isolated from other possible faults in the system. The group-wise fault isolation is based directly on the input/output signals applied for the fault detection. It is guaranteed that the fault group includes the fault that had occurred in the system. The second step is individual fault isolation in the fault group. Both types of isolation are obtained by applying dedicated auxiliary inputs and the associated residual outputs.
This paper describes a new method for how interfering MIMO links might transmit more effectively in a random access network. We assume perfect transmitter-side channel state information, zero-forcing pre-coding to gua...
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This paper describes a new method for how interfering MIMO links might transmit more effectively in a random access network. We assume perfect transmitter-side channel state information, zero-forcing pre-coding to guarantee no interference on links that have already won access, and zero-forcing receiver processing at the still-contending links to suppress interference from the links that have already won. We define an effectiveness metric, the Instantaneous Equivalent SNR Percentile (IESP), in which the Equivalent SNR is the SNR of a single-input-single-output (SISO) link that would have the same capacity of a MIMO link after its interference constraints have been met and the IESP is the percentile of the Equivalent SNR, assuming independent Rayleigh fading. We propose that fairness among heterogeneous contending links be realized by giving the shorter contention window to the link with the higher IESP based on its own distribution, enabling links with few antennas to compete with links that have many antennas. Through simulation of the sum capacity of the winning set of links, the proposed contention window design is shown to provide a higher sum capacity than contention based on equal-sized windows.
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