The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform

Yangquan Chen - One of the best experts on this subject based on the ideXlab platform.

  • multiple uav formations for cooperative source seeking and Contour Mapping of a radiative signal field
    Journal of Intelligent and Robotic Systems, 2014
    Co-Authors: Jinlu Han, Yangquan Chen
    Abstract:

    In this paper, four scenarios are presented for cooperative source seeking and Contour Mapping of a radiative signal field by multiple UAV formations. A source seeking strategy is adopted with saturation, and then it is modified to achieve Contour Mapping of the signal field with the moving source situation considered. A formation controller used for consensus problem is simplified and applied in the scenarios to stabilize the multiple UAV formation flight during source detection. The Contour Mapping strategy and the formation control algorithm are combined to guarantee stable source seeking and Contour Mapping in both circular flight path and square flight path via multiple UAV formations.

  • cooperative source seeking and Contour Mapping of a diffusive signal field by formations of multiple uavs
    International Conference on Unmanned Aircraft Systems, 2013
    Co-Authors: Jinlu Han, Yangquan Chen
    Abstract:

    This paper presents three scenarios using multiple UAVs based cooperative source seeking strategy to locate the position of a diffusive signal field and Contour Mapping via cooperative multiple UAVs with circular formation flight. An existing source seeking algorithm is adopted and improved in this paper for better signal source locating, then the algorithm is modified to achieve Contour Mapping of the signal field. A formation control strategy used for consensus problem is simplified and applied in this paper to stabilize the UAVs formation flight during detection. The Contour Mapping algorithm and the formation control strategy are combined to guarantee the Contour Mapping of the diffusive signal field via cooperations of multiple UAVs.

  • Low-cost Multi-UAV Technologies for Contour Mapping of Nuclear Radiation Field
    Journal of Intelligent and Robotic Systems, 2012
    Co-Authors: Jinlu Han, Yangquan Chen
    Abstract:

    Low cost UAVs are becoming more and more popular in both research and practical applications, and it leads to a new, potentially significant service product known as UAV-based personal remote sensing (PRS). Multi-UAV system with advanced cooperative control algorithms has advantages over single UAV system, especially in time urgent tasks such as detecting nuclear radiation before deploying the salvage. This paper considers two scenarios for nuclear radiation detection using multiple UAVs, of which Contour Mapping of the nuclear radiation is simulated. Then, for real applications, this paper presents a low-cost UAV platform with built-in formation flight control architecture together with a formulated standard flight test routine. Three experimental formation flight scenarios that imitate the nuclear detection missions are prepared for Contour Mapping of nuclear radiation field in 3D space.

Yunhao Liu - One of the best experts on this subject based on the ideXlab platform.

  • iso map energy efficient Contour Mapping in wireless sensor networks
    International Conference on Distributed Computing Systems, 2007
    Co-Authors: Yunhao Liu
    Abstract:

    Contour Mapping is a crucial part of many wireless sensor network applications. Many efforts have been made to avoid collecting data from all the sensors in the network and producing maps at the sink, which is proven to be inefficient. The existing approaches (often aggregation based), however, suffer from heavy transmission traffic and incur large computational overheads on each sensor node. We propose Iso-Map, an energy-efficient protocol for Contour Mapping, which builds Contour maps based solely on the reports collected from intelligently selected "isoline nodes" in wireless sensor networks. Iso-Map achieves high-quality Contour Mapping while significantly reducing the generated traffic from O(n) to O(radicn), where n is the total number of sensor nodes in the field. The per-node computation overhead is also restrained as a constant. We conduct comprehensive trace-driven simulations to verify this protocol, and demonstrate that Iso-Map outperforms the previous approaches in the sense that it produces Contour maps of high fidelity with significantly reduced energy cost.

Limin Sun - One of the best experts on this subject based on the ideXlab platform.

  • energy efficient Contour Mapping aggregation in wireless sensor networks
    Static Analysis Symposium, 2010
    Co-Authors: Yan Liu, Xinyun Zhou, Limin Sun
    Abstract:

    Contour Mapping is an energy-efficient method for geographic correlated value monitoring in Wireless Sensor Networks(WSNs), it suppresses reporting nodes by selecting nodes that are on a Contour line. A sensor network is often densely deployed in applications such as temperature or humidity monitoring. In these applications, Contour Mapping plays a crucial role in data aggregation and data transmission reduction when nodes are densely deployed. In this paper, we propose a novel scheme called DABC (data aggregation based on Bezier curves) to implementing Contour Mapping in WSNs. In DABC algorithm, sensor nodes that play as sources to report to the sink are intelligently selected through method based on Bezier curve. Simulation on a temperature monitoring scenario shows that DABC saves an amount of energy while achieves almost same fidelity of Contour Mapping, comparing with traditional methods.

M Chao - One of the best experts on this subject based on the ideXlab platform.

  • automated Contour Mapping with a regional deformable model
    International Journal of Radiation Oncology Biology Physics, 2008
    Co-Authors: M Chao, E Schreibmann, Albert C Koong, Lei Xing
    Abstract:

    Purpose To develop a regional narrow-band algorithm to auto-propagate the Contour surface of a region of interest (ROI) from one phase to other phases of four-dimensional computed tomography (4D-CT). Methods and Materials The ROI Contours were manually delineated on a selected phase of 4D-CT. A narrow band encompassing the ROI boundary was created on the image and used as a compact representation of the ROI surface. A BSpline deformable registration was performed to map the band to other phases. A Mattes mutual information was used as the metric function, and the limited memory Broyden-Fletcher-Goldfarb-Shanno algorithm was used to optimize the function. After registration the deformation field was extracted and used to transform the manual Contours to other phases. Bidirectional Contour Mapping was introduced to evaluate the proposed technique. The new algorithm was tested on synthetic images and applied to 4D-CT images of 4 thoracic patients and a head-and-neck Cone-beam CT case. Results Application of the algorithm to synthetic images and Cone-beam CT images indicates that an accuracy of 1.0 mm is achievable and that 4D-CT images show a spatial accuracy better than 1.5 mm for ROI Mappings between adjacent phases, and 3 mm in opposite-phase Mapping. Compared with whole image–based calculations, the computation was an order of magnitude more efficient, in addition to the much-reduced computer memory consumption. Conclusions A narrow-band model is an efficient way for Contour Mapping and should find widespread application in future 4D treatment planning.

  • automated Contour Mapping using sparse volume sampling for 4d radiation therapy
    Medical Physics, 2007
    Co-Authors: M Chao, E Schreibmann, T Li, Nicole M Wink, L Xing
    Abstract:

    The purpose of this work is to develop a novel strategy to automatically map organ Contours from one phase of respiration to all other phases on a four-dimensional computed tomography (4D CT). A region of interest (ROI) was manually delineated by a physician on one phase specific image set of a 4D CT. A number of cubic control volumes of the size of ∼ 1 cm were automatically placed along the Contours. The control volumes were then collectively mapped to the next phase using a rigid transformation. To accommodate organ deformation, a model-based adaptation of the control volume positions was followed after the rigid Mapping procedure. This further adjustment of control volume positions was performed by minimizing an energy function which balances the tendency for the control volumes to move to their correspondences with the desire to maintain similar image features and shape integrity of the Contour. The mapped ROI surface was then constructed based on the central positions of the control volumes using a triangulated surface construction technique. The proposed technique was assessed using a digital phantom and 4D CTimages of three lung patients. Our digital phantom study data indicated that a spatial accuracy better than 2.5 mm is achievable using the proposed technique. The patient study showed a similar level of accuracy. In addition, the computational speed of our algorithm was significantly improved as compared with a conventional deformable registration-based Contour Mapping technique. The robustness and accuracy of this approach make it a valuable tool for the efficient use of the available spatial-tempo information for 4D simulation and treatment.

Jinlu Han - One of the best experts on this subject based on the ideXlab platform.

  • multiple uav formations for cooperative source seeking and Contour Mapping of a radiative signal field
    Journal of Intelligent and Robotic Systems, 2014
    Co-Authors: Jinlu Han, Yangquan Chen
    Abstract:

    In this paper, four scenarios are presented for cooperative source seeking and Contour Mapping of a radiative signal field by multiple UAV formations. A source seeking strategy is adopted with saturation, and then it is modified to achieve Contour Mapping of the signal field with the moving source situation considered. A formation controller used for consensus problem is simplified and applied in the scenarios to stabilize the multiple UAV formation flight during source detection. The Contour Mapping strategy and the formation control algorithm are combined to guarantee stable source seeking and Contour Mapping in both circular flight path and square flight path via multiple UAV formations.

  • cooperative source seeking and Contour Mapping of a diffusive signal field by formations of multiple uavs
    International Conference on Unmanned Aircraft Systems, 2013
    Co-Authors: Jinlu Han, Yangquan Chen
    Abstract:

    This paper presents three scenarios using multiple UAVs based cooperative source seeking strategy to locate the position of a diffusive signal field and Contour Mapping via cooperative multiple UAVs with circular formation flight. An existing source seeking algorithm is adopted and improved in this paper for better signal source locating, then the algorithm is modified to achieve Contour Mapping of the signal field. A formation control strategy used for consensus problem is simplified and applied in this paper to stabilize the UAVs formation flight during detection. The Contour Mapping algorithm and the formation control strategy are combined to guarantee the Contour Mapping of the diffusive signal field via cooperations of multiple UAVs.

  • Low-cost Multi-UAV Technologies for Contour Mapping of Nuclear Radiation Field
    Journal of Intelligent and Robotic Systems, 2012
    Co-Authors: Jinlu Han, Yangquan Chen
    Abstract:

    Low cost UAVs are becoming more and more popular in both research and practical applications, and it leads to a new, potentially significant service product known as UAV-based personal remote sensing (PRS). Multi-UAV system with advanced cooperative control algorithms has advantages over single UAV system, especially in time urgent tasks such as detecting nuclear radiation before deploying the salvage. This paper considers two scenarios for nuclear radiation detection using multiple UAVs, of which Contour Mapping of the nuclear radiation is simulated. Then, for real applications, this paper presents a low-cost UAV platform with built-in formation flight control architecture together with a formulated standard flight test routine. Three experimental formation flight scenarios that imitate the nuclear detection missions are prepared for Contour Mapping of nuclear radiation field in 3D space.