Radial harmonic-Fourier moments (RHFMs) are popular for image reconstruction and invariant pattern recognition due to their properties of translation, scaling and rotation invariant. RHFMs possess lower computation co...
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Radial harmonic-Fourier moments (RHFMs) are popular for image reconstruction and invariant pattern recognition due to their properties of translation, scaling and rotation invariant. RHFMs possess lower computation complexity as compared to Zernike moments and Bessel-Fourier moments. However, they always suffer from discontinuity, numerical instability near the center of image, and reconstruction error, especially have a rise for higher order of moments. In this paper, an improvement of radial harmonic-Fourier moments (IRHFMs) is proposed for effectively avoiding the above-mentioned *** this paper, a 2D fast Fourier transform algorithm also is applied to the image matrix to obtain the IRHFMs. Simulation experimental results demonstrate the proposed IRHFMs perform better than traditional RHFMs and other classic orthogonal moments including the latest image moments, for example, polar harmonic Fourier moments in terms of the image reconstruction capability and rotation invariant recognition accuracy in noise-free and noisy conditions.
In this study, we propose a power-efficient ZF precoding scheme for visible light communication (VLC) downlink multi-user multiple-input-single-output (MU-MISO) systems, which incorporates the zero-forcing (ZF) and th...
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In this study, we propose a power-efficient ZF precoding scheme for visible light communication (VLC) downlink multi-user multiple-input-single-output (MU-MISO) systems, which incorporates the zero-forcing (ZF) and the characteristics of VLC systems. The main idea of this scheme is that the channel matrix used to perform pseudoinverse comes from the set of optical Access Points (APs) shared by more than one user, instead of the set of all involved serving APs as the existing ZF precoding schemes often used. By doing this, the waste of power, which is caused by the transmission of one user's data in the un-serving APs, can be avoided. In addition, the size of the channel matrix needs to perform pseudoinverse becomes smaller, which helps to reduce the computation complexity. Simulation results in two scenarios show that the proposed ZF precoding scheme has higher power efficiency, better bit error rate (BER) performance and lower computation complexity compared with traditional ZF precoding schemes.
This study proposes a method to handle unrecoverable data using a formula called Bezier curve. The proposed method suggests the possibility to approximate the damaged data, which have been processed by the error corre...
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This study proposes a method to handle unrecoverable data using a formula called Bezier curve. The proposed method suggests the possibility to approximate the damaged data, which have been processed by the error correction scheme. The proposed method works on the real-time distributed system which retransmission is considered as unsuitable solution to manage the overall networked system. By using the Bezier curve, the transmitted unrecoverable data are reconstructed again by using the functional approximation. This method provides a smoothing effect on damaged data that usually are normalised on real-time transmission of PROFIBUS. Three differences Bezier curve methods are compared in PROFIBUS data, four-points (FP) method, two-points two-degrees method and four-degrees (FD) method. Simulation results show that all three Bezier curve methods can approximate data in PROFIBUS. FD has higher computation complexity compared with others. However, FD compensates with its data size which is only half of FP method.
The article considers a distributed divide-and-conquer method to test the mutual independence between components of massive multivariate data. In particular, a new test statistic based on U-statistics by dividing the ...
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The article considers a distributed divide-and-conquer method to test the mutual independence between components of massive multivariate data. In particular, a new test statistic based on U-statistics by dividing the full data samples into disjoint blocks will be established. Some numerical simulations and real data analysis demonstrate that the proposed method is effective, and it can significantly reduce the computational complexity and save the running time of the test procedure on massive data inference.
The common outage performance of an amplify-and-forward two-hop two-user channel is studied in the presence of multiple independent interferers at the destination. First, the exact integral form expression of the comm...
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The common outage performance of an amplify-and-forward two-hop two-user channel is studied in the presence of multiple independent interferers at the destination. First, the exact integral form expression of the common outage probability is derived. Then, in order to decrease the computation complexity, a closed-form approximation of the common outage probability is derived. Finally, the asymptotic analysis is performed based on the approximation expression. Numerical results demonstrate that the integral form of the common outage probability, the corresponding approximation and the asymptotic results match well with the Monte Carlo simulations.
Sum of absolute Hadamard transformed differences (SATD) is an important distortion metric applied in the latest video coding standard H.264/AVC, which is an alternative to the sum of absolute differences (SAD) to impr...
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Sum of absolute Hadamard transformed differences (SATD) is an important distortion metric applied in the latest video coding standard H.264/AVC, which is an alternative to the sum of absolute differences (SAD) to improve coding efficiency. However, the SATD requires more computation load due to the Hadamard transform involved. Inspired by a geometric interpretation of the simplest two-point SATD calculation, an efficient way to compute the SATD is proposed, which considers the joint effect of the Hadamard transform and the following SAD processing in the SATD calculation and thus enables the computation of SATD without performing the Hadamard transform separately. We further extend the two-point transform-exempted SATD (TE-SATD) computation scheme to four-point and 4 x 4 block SATD calculation. With the same coding performance, the proposed TE-SATD-based fast algorithms can save 38% and 17% operations in computing a 4 x 4 block SATD compared with the conventional SATD calculation and the fast Hadamard transform-based calculation, respectively.
Thin plates are widely used in engineering, so it is of great value to explore energy harvester based on this type of structure. Acoustic black hole (ABH) is helpful for the energy harvesting of thin plate. However, t...
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Thin plates are widely used in engineering, so it is of great value to explore energy harvester based on this type of structure. Acoustic black hole (ABH) is helpful for the energy harvesting of thin plate. However, the traditional power-law ABH needs to be improved in the low-frequency energy harvesting. Thereupon, a new Eulerian exponential law for ABH is proposed, and a 2-D ABH structure based on the Eulerian exponential law is designed for harvesting low-frequency energy. This article constructs a simple electromechanical coupling dynamic model for the Eulerian-exponential-law ABH energy harvester (EAEH). This model has low computation complexity as the dimension of thin plate is reduced by the Kronecker product of x- and y-direction beams' modes. Combining the element division and modal analysis of beam, a new method with high computational efficiency is proposed for calculating the base functions of thin plate with 2-D ABH, and its effectiveness and accuracy are validated by the result of finite-element analysis. Under different excitation frequencies, the voltage and power responses of EAEH are simulated, and their validity is verified by the experimental results. Moreover, EAEH is compared with the power-law ABH energy harvester through the simulation and experiment. The comparative results show that EAEH has lower resonant frequencies and higher output of voltage and power.
Six-DoF (Six-degree-of-freedom) pose localization based on 3D point clouds is a challenging task for LBSs (localization-based services). This paper proposes a robust and efficient method that uses multimodal informati...
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Six-DoF (Six-degree-of-freedom) pose localization based on 3D point clouds is a challenging task for LBSs (localization-based services). This paper proposes a robust and efficient method that uses multimodal information (vision and Wi-Fi signal information) to estimate the 6-DoF pose of an RGBD camera on a robot with respect to complex 3D textured models of the indoor environment that can contain more than 650,000,000 points. Our developed method narrows the search scope, which delimits boundaries initially using the Wi-Fi location system and applies an environment-adaptive approach to determine the radius of the search sphere based on the signal stability of the Wi-Fi location system. In addition, we propose an algorithm for estimating a novel correspondence between local points with a 3D submap by combining 3D points and surface normals to acquire absolute poses from noisy and outlier-contaminated matching point sets for RGBD sensors in dynamic indoor scenes. Then, a novel two-level spatial verification strategy is used to estimate an accurate pose, which includes the use of a RANSAC (Random Sample Consensus) algorithm for identification and a direct least-square method to acquire the pose from the inliers. The proposed method has been implemented and tested extensively in various indoor scenes. The experimental results demonstrate that the Wi-Fi-aided localization system can efficiently localize a mobile robot in a variety of large-scale 3D point cloud datasets to realize stable time consumption and similar performance to state-of-the-art methods.
We introduce a family of tableau calculi for deontic action logics based on finite boolean algebras (or DAL for short), these logics provide deontic operators (e.g., obligation, permission, prohibition) which are appl...
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We introduce a family of tableau calculi for deontic action logics based on finite boolean algebras (or DAL for short), these logics provide deontic operators (e.g., obligation, permission, prohibition) which are applied to a finite number of actions (the vocabulary of the logic);furthermore, in these formalisms, actions can be combined by means of boolean operators, this provides an expressive algebra of actions. We define a tableau calculus for the basic logic and then we extend this calculus to cope with extant variations of this formalism;we prove the soundness and completeness of these proof systems. In addition, we investigate the computational complexity of the satisfiability problem for DAL and its extensions;we show this problem is NP-complete when the number of actions considered is fixed, and it is -Hard (in Stockmeyer's polynomial hierarchy) when the number of actions is taken as an extra parameter. The tableau systems introduced here can be implemented in PSPACE, this seems reasonable taking into consideration the computational complexity of the logics.
In this article, we present a solution to a class of Quasi-Birth-and-Death processes with finite state space and show that the stationary probability vector has a matrix geometric representation. We show that such mod...
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In this article, we present a solution to a class of Quasi-Birth-and-Death processes with finite state space and show that the stationary probability vector has a matrix geometric representation. We show that such models have a level-dependent rate matrix. The corresponding rate matrix is given explicitly in terms of the model parameters. The resulting closed-form expression is proposed as a basis for efficient calculation of the stationary probabilities. The method proposed in this article can be applied to several queueing systems.
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