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A filtered ghost imaging (GI) protocol is proposed that enables the Rayleigh diffraction limit to be exceeded in an intensity correlation system; a super-resolution reconstructed image is achieved by low-pass filtering of the measured intensities. In a lensless GI experiment performed with spatial bandpass filtering, the spatial resolution can exceed the Rayleigh diffraction bound by more than a factor of 10. The resolution depends on the bandwidth of the filter, and the relationship between the two is investigated and discussed. In combination with compressed sensing programming, not only high resolution can be maintained but also image quality can be improved, while a much lower sampling number is sufficient.

Chinese calligraphy is a charismatic ancient art form with high artistic value in Chinese culture. Virtual calligraphy learning system is a research hotspot in recent years. In such system, a judging mechanism for user’s practice result is quite important. Sometimes, user’s handwritten character is not that standard, the size and position are not fixed, and the whole character may be even askew, which brings difficulty for its evaluation. In this paper, we propose an approach by using DBSCs (disk B-spline curves) vectorization and ICP (iterative closest point) algorithm, which cannot only evaluate a calligraphic character without knowing what it is, but also deal with the above problems commendably. Firstly we find the promising candidate characters from the database according to the angular difference relations as quickly as possible. Then we check these vectorized candidates by using ICP algorithm based upon the skeleton, hence finding out the best matching character. Finally a comprehensive evaluation involving global (the whole character) and local (strokes) similarities is implemented, and a final composited evaluation score can be worked out.

A piezoelectric driving method for rover vehicles is proposed in this paper. Employing this method, a tracked vehicle driven by friction forces from a frame mounted with piezoelectric elements was developed. The vehicle is designed with no driver sprocket, no idler-wheel and no supporting bogie wheels, and the vehicle thus requires no lubrication and has potential application in planetary exploration. The frame consists of a pair of piezoelectric transducers. Each transducer comprises four annular parts jointed by beams adhered with piezoelectric ceramics. The tracks are set to the outer surface of the annular parts by means of track tension. Traveling rotating waves are generated by piezoelectric transducers in the annular parts, which generate microscopic elliptical motions at the interface of the tracks. The microscopic elliptical motions from the piezoelectric transducers drive the track vehicle to move. Finite elements analysis was carried out to verify the operation principle using commercial software ANSYS. Piezoelectric transducers were fabricated, assembled and tested to validate the concepts of the proposed rover vehicle and confirm the simulation results. A prototype vehicle with mass of 0.57 kg moves at a speed of 4.3 mm/s at a driving voltage of 250 V and operating frequency of 65.53 kHz. Robotic exploration of the lunar surface will provide important scientific data on climate, life history, and geologic resources. Landers and rovers for lunar exploration have been researched in recent decades. The main aim of research into lunar robotics exploration is to demonstrate technologies suitable for exploration of the lunar surface, including driving technologies for rover vehicles. Efficient rover vehicles that are compact, lightweight and consume little power are needed to meet the needs of lunar missions [1]. Five classes of locomotion systems are applicable to lunar/planetary exploration rovers: wheel, track, leg, bodyarticulation, and non-contact locomotion systems [2]. The chief advantage of legged robots is that they only need to overcome compaction resistance at the point of contact while wheeled and tracked robots that are considerably more complex than algorithms for wheeled and tracked systems. Among the above mentioned types of mobility system, wheeled and tracked systems have been considered the main candidates for planetary exploration, especially the exploration of Mars, in recent decades wide applications on Earth.The tracked (or caterpillar) concept is promising in that it offers low maximum ground pressure to promote vehicle performance (especially in the case of military vehicles) [3]. Tracks are generally preferred for general off-road applications as they offer low vehicle sinkage and thus low resistance to motion. Tracked vehicles have similar properties to wheeled vehicles and are generally favored for their higher tractional effort over more rugged terrain as they spread the load over a much wider area; a tracked vehicle will almost invariably offer greater drawbar pull than a fou...

At present, qualitative spatial reasoning has become the hot issues in many research fields. The most popular models of spatial topological relations are Region Connection Calculus (RCC) and 9-intersection model. However, there are few contributions on topological relations of concave regions in which the representative model is Cohn's RCC23. There are some limitations of RCC23 especially in practical applications due to its less expressiveness. In order to construct a more expressive model of topological relations between concave regions, this paper completed the following works: 9-intersection matrix is extended to 16-intersection matrix, and RCC23 is refined to RCC62 based on 16intersection matrix. More relations can be distinguished in RCC62, which is more expressive than RCC23. In order to further reason about relations in RCC62, the Conceptual Neighborhood Graph (CNG) and the Closest Topological Relation Graph (CTRG) of RCC62 are given.