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Sensing falsification is a key security threat in cooperative spectrum sensing in cognitive radio networks. Intelligent malicious users (IMUs) adjust their malicious behaviors according to their objectives and the network’s defense schemes. Without long-term collection of information on users’ reputation, the existing schemes fail to thwart such malicious behaviors. In this paper, we construct a joint...
Quadruped robots are required to implement a fast transition between gaits in situations such as an abruptly increase in speed, an unexpected obstacle to stride over. Considering these situations, we propose a novel approach to achieve fast gait transition within a step cycle period of locomotion. This approach relies on the central pattern generators (CPGs) to produce rhythmic control signals, along...
In this paper we analyze characteristics of the ground reaction force (GRF) experienced by the legs of the quadruped robot during stance phase in walk gait, in particular, when the height of center of gravity (COG) of the quadruped robot is changeable. We also build the dynamics model of the quadruped robot. Two dynamics equations during swing phase and stance phase are established, respectively....
The joint maximum likelihood sequence estimation (JMLSE) is a useful algorithm for the single-antenna co-channel interference cancellation. But the conventional JMLSE algorithm is only suitable for continuous signal. If burst signals are processed as continuous signals, the conventional JMLSE will suffer an error floor. To overcome this problem, a modified JMLSE algorithm was proposed for burst digital...
Distributive service data storage at the caching-enabled base stations (BSs) can reduce the traffic load in future cellular networks. Taking the limited caching space into account, it is necessary for the BSs to adjust their caching data based on service popularity in order to achieve better caching efficiency. In this paper, we investigate the cache replacement strategy for BSs to minimize the transmission...
The trajectory planning in the case of grasping a space target is researched in this paper for a reconfigurable mobile robot, Joint Locomotion - 2 (JL-2), in the Mobile Manipulating (MM) mode. The trajectory is composed of three segments, including the robot locomotion trajectory in plane generated by a cubic polynomial function, the trajectories of the end-effector adjusting its posture and approaching...
In practice, under communication bandwidth constraints, raw measurements are not generally sent to the fusion center. Therefore, it is a very real problem that how to generate correct decentralized estimation of target state and sensor systematic error when one use track outputs of multiple sensors without bias calibration to finish distributed fusion. Based on Bayesian filtering equations and equivalent...
Coherent joint transmission (CJT) algorithm has been extensively investigated in multi-cell cooperative downlink transmission due to its huge potential performance gains. Comparing with the existing CJT algorithm based on the multi-user eign-mode transmission, an enhanced CJT (eCJT) algorithm is proposed in this paper to further enhance the performance of cellular network in terms of spectral efficiency,...
Sensing falsification is a key security problem in cooperative spectrum sensing for cognitive radio networks. Most previous approaches assume that malicious users only cheat in their sensing reports following a predefined rule. However, some malicious users usually act intelligently to strategically adjust their malicious behavior according to their objectives and the network's defense schemes. The...
Locomotion on rough terrain is a critical and basic capability for quadruped robots. In this paper, we present a gait planning approach of crossing planar obstacles for a quadruped robot. The system is composed by rhythmic motion generation and gait planning algorithm. Rhythmic motion generation is mainly composed of two parts: the Central Pattern Generator (CPG) model based on the Holf oscillator...
This paper investigates the problem of cross-modal retrieval, where users can search results across various modalities by submitting any modality of query. Since the query and its retrieved results can be of different modalities, how to measure the content similarity between different modalities of data remains a challenge. To address this problem, we propose a joint graph regularized multi-modal...
One major disadvantage of OFDM is its high sensitivity to phase noise introduced by local oscillators. Although several algorithms have been addressed in the literature to mitigate the effects of phase noise, there are two unsolvable problems for the current study of phase noise suppression that the CPE correction algorithms are based on the perfect channel state information and the ICI suppression...
Synthetic Aperture Radar (SAR) signal model is considered as a series of echo signals in range direction. The procedure of Principal Component Analysis (PCA) is introduced which is used as transformation basis to sparsify the SAR signals. The joint Compressive Sensing (CS) and PCA algorithm is derived to realize SAR raw data sparse and compressive measurement. The numerical simulation results demonstrate...
Aiming to reduce the computation and implement compliant control, this paper proposes a novel inverse dynamics control strategy based on the floating-base rigid body system. The control strategy assumes that each leg of the quadruped robot organizes itself into an independent autonomous system, a serial robot. Based on this assumption, the kinematics and the dynamics models of the quadruped robot...
In cognitive radio networks, multiple discontinuous spectrum opportunities are detected by spectrum sensing and utilized together to satisfy the service requirement by spectrum aggregation. In this paper, we develop an analytical framework for joint spectrum sensing and access scheme based on Partially Observable Markov Decision Process (POMDP). Considering the hardware limitations, the spectrum aggregation...
In this paper we address the turning maneuver technique for a quadruped robot with only the hip pitch and the knee pitch for each leg, and explore characteristics of the mediolateral reaction forces experienced by the robot legs during the stance phase. We propose a turning strategy based on the translation of the hip-knee joint space towards the deepest flexion point. Such a translation can cause...
This paper proposes a control method of trajectory planning and posture adjustment for quadruped robots' obstacle striding. The addressed mixed parabola method plans the travelling paths over obstacles in Cartesian coordinate system. The constraints on velocities, accelerations, and jerks at waypoints are employed to generate the time-efficient smooth cubic spline joint trajectories by nonlinear optimization...
The markerless vision-based human motion parameters capturing has been widely applied for human-machine interface. However, it faces two problems: the high-dimensional parameter estimation and the self-occlusion. Here, we propose a 3-D human model with structural, kinematic, and temporal constraints to track a walking human object in any viewing direction. Our method modifies the Annealed Particle...
The development of modern integrative transportation system calls for the reform of the traffic management system objectively. The analysis of the experience of traffic management in foreign developed countries suggests that Chinese traffic administrative management should be centralized in terms of authority structure, separated between the powers of policy-making and execution in terms of authority...
Under the new situation of ‘Cairns Decision’ limitation of the numbers of world heritage declaration for each country, the approach of inter-regional bundled world heritage declaration is created to break through the restrictions, as well as an important way out for China to declare for world heritage. Based on analyzing the characteristics of inter-regional bundled world heritage, this paper discusses...
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