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We derive a new fast convergent Density Evolution algorithm for finding optimal rate Low-Density Parity-Check (LDPC) codes used over the binary erasure channel (BEC). The fast convergence property comes from the modified Density Evolution (DE), a numerical method for analyzing the behavior of iterative decoding convergence of a LDPC code. We have used the method of [16] for designing of a LDPC code...
In order to overcome the premature convergence problem of clonal selection algorithm (CSA), a hybrid quantum crossover is proposed to improve the performance of CSA. The hybrid crossover is composed of two crossovers and well balance the exploration and exploitation search during immune maturation process. The effectiveness of the new crossover based CSA is evaluated on a class of traveling salesman...
Synchronous iterative algorithms are often less scalable than asynchronous iterative ones. Performing large scale experiments with different kind of network parameters is not easy because with supercomputers such parameters are fixed. So, one solution consists in using simulations first in order to analyze what parameters could influence or not the behavior of an algorithm. In this paper, we show...
In the study, the authors solve the problem of uniform global K-exponential stabilization for an non-symmetric underactuated surface vessel with only two available inputs. Using coordinate transformations and Lyapunov theory, a smooth time-varying control law is proposed under certain conditions on the inertia and damping matrices, gives global K-exponential stability of the closed-loop system. Finally,...
This paper develops a kinematic path-tracking algorithm for a nonholonomic mobile robot using an improved iterative learning control (I-ILC) technique. The proposed algorithm produces a velocity command to the wheeled robot, in addition, the state disturbances and measurement noises are taken into consideration. In the learning rule, an adjustable parameter is defined and by adjusting this parameter...
The autonomous obstacle avoidance planning of USV is the guarantee and the precondition of carrying out the performance. Obstacle avoidance planning is required to possess high accuracy and instantaneity due to a complex environment and faster speed. The algorithm of Artificial Potential Field has the advantage of sample mathematical model, which is easy to understand and implement, and facilitate...
To enhance the dynamic and static performance of the extremum seeking scheme (ESS), a novel fast ESS without the steady-state oscillation is proposed by adjusting the structure of the classic ESS to make the sinusoidal excitation signal amplitude proportional to the absolute value of the extremum estimation error. The improved ESS can speed up the convergence to shorten the seeking time dramatically,...
In this paper, the problem of relative position control for rigid spacecraft in rendezvous and docking is investigated. We propose a control scheme with finite-time convergence based on the linearized dynamic model obtained from the Hill-Clohessy-Wiltshire (HCW) equations, in the presence of external disturbance. By constructing a particular Lyapunov function, we confirm the convergence of the proposed...
Based on the kinematics and dynamics of missile-to-target relative motion and the method of time-to-go estimation, a biased proportional guidance (BPG) law that can reduce the impact time variance is designed and proved. Then a time cooperative guidance law with impact angle constraint for two missile formations is designed, based on the guidance law with terminal angle constraint. The impact angle...
This paper compares three sliding mode control laws for nano-positioning systems using piezoelectric actuators (PEAs), where the hysteresis nonlinearity can be viewed as the uncertainties of the system. Compared with the other control laws, sliding mode based controllers (SMC) are proved to be an effective method that specifically appealing to uncertainties and disturbances. To avoid the chattering...
An adaptive ant colony algorithm is proposed to overcome the premature convergence problem in the conventional ant colony algorithm. The adaptive ant colony is composed of three groups of ants: ordinary ants, abnormal ants and random ants. Each ordinary ant searches the path with the high concentration pheromone at the high probability, each abnormal ant searches the path with the high concentration...
In this paper, a novel control method is proposed for single-input single-output second-order nonlinear systems. The proposed controller guarantees the system reach to the sliding mode surface from any initial states and converge to origin along the surface in finite time while solving the problem of singularity. Compared with traditional fast terminal sliding mode (FTSM) controller, the proposed...
In this paper, we study cooperative control problems with a multi-UAV system. Specifically, we propose a c consensus-based cooperative formation control strategy with collision-avoidance capability for a group of multiple unmanned aerial vehicles (UAVs). To cooperatively fly in formation, a consensus-based algorithm and a leader-follower structure are applied to the UAVs. Collisions among the UAVs...
A time-varying controller is proposed to simultaneously solve the stabilization and the tracking problem of wheeled mobile robots via their equivalent chained form. The control is designed based on Lyapunov's direct method and the backstepping technique. The outstanding feature of the proposed controller is computationally simple due to its full use of the existing results on stabilization and tracking...
Real-time price is the most ideal pricing mechanism in power market. Therefore, study on real-time price algorithm has profound theoretical and practical significance in smart grid. In this paper, we propose an improved real-time pricing algorithm to solve the problems of bad convergence and applicable conditions of this existing optimal real-time pricing model based on utility maximization. First,...
Consensus algorithm is widely used for Cooperative Spectrum Sensing (CSS) in Cognitive Radio Networks (CRNs). However, using this method, much of time and energy consumption for cooperation is wasted by repeatedly recirculating redundant information. We propose a novel Contextual Binary Gossip (CBG) algorithm for CSS. Utilizing the contextual information, two Secondary Users (SUs) will exchange sensing...
A unified observer of high order disturbances in time series expansion for a class of nonlinear systems was proposed in this paper. The stability of a special observer from selecting the nonlinear weighted function was analyzed for constant disturbance. Then the constant disturbance observer algorithm was generalized to ramp disturbance and high order disturbances in time series expansion by incorporating...
Due to the in-network caching capability, Content-Centric Networking (CCN) has emerged as one of the most promising architectures for the diffusion of contents over the Internet. In this paper, we propose an energy-efficient distributed in-network caching scheme for CCN. In the proposed scheme, each content router only needs locally available information to make caching decisions considering both...
The transition to agent-based competitive wholesale and retail markets for electric utilities around the world has been a difficult and controversial process. One of the difficulties that hindered the development and growth of a competitive power market is the absence of efficient computational tools to assist the design, analysis and operation of the power market. This paper investigates mathematical...
This paper propose a new maximum power point tracker called fractional order extremum seeking control for grid-connected photovoltaic (PV) systems tasks to better accommodate rapid varying solar irradiance for photovoltaic (PV) arrays. The new algorithm is benchmarked against the integer order extremum seeking control and incremental conductance algorithms. Our extensive simulation results show that...
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