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Gravity gradient measurement satellite is a kind of drag-free satellite and suffers from multiple disturbances in the low earth orbit. So the disturbances estimation and compensation for the drag-free satellite is very important to improve measurement precision. In this paper, the characteristics of multiple disturbances are analyzed. Then, the frequency domain disturbance observer is designed for disturbance estimation and compensation. Next, a composite controller combining the frequency domain disturbance observer with PID controller is presented to reject and attenuate the multiple disturbances. At last, the simulation verification is carried out to verify the effectiveness of the proposed method.

Human pose estimation in monocular still image is a hotspot and difficult issue in the computer vision field, and it has important applicable to many novel area. However, the detecting rate is still poor due to many factors as variety of pose and clothing, occlusion, clustering background etc. A pose estimation approach combining deformable part model and full body model is presented to solve the problem of mistaking part orientation caused by the detecting error for body location. We use full body model to augment the spatial position of full body with head-shoulder detector. We find that the whole body location is benefit to capture human body parts. The experimental results on PARSE dataset show that our approach outperforms many past studies for several body parts.

For a comprehensive and objective understanding of the dynamic overload of armor-piercing bullet penetrating steel target, it must be processed of nonsteady penetrating acceleration signals. In this article, acceleration signals, which are obtained by the embedded high-overload electronic solid recorder at the test of armor-piercing bullet penetrating steel target, is done of wave filtering and integral analysis and so on in time domain, frequency-domain analysis through FFT, as well as Wigner-Ville time-frequency analysis and wavelet analysis. It is obtained of the characteristic signal when armor-piercing bullet penetrates steel target under certain conditions. Through signal processing and comprehensive analysis, the trait of armor-piercing bullet penetrating steel target is obtained, also a kind of data processing method is provided to engineers, by which concerned parameters can be got.

Complex event detection in stream is an important problem in event stream processing field. In this paper, we propose a new complex event detection algorithm in probabilistic stream, Instance Pruning and Filter-Detection Algorithm (IPF-DA). This algorithm is based on a kind of data structure called Chain Instance Queues (CIQ), to detect complex events satisfying query requirements with single-scanning probabilistic stream. In the process of complex event detection, IPF-DA prunes unnecessary event instances with query requirements and achieves filter for complex events with the given threshold. And it further improves the efficiency by setting proper tolerance, while insuring high recall. In addition, we construct Bayesian network to express and infer the probability distribution of uncertain events. Conditional Probability Indexing-Tree (CPI-Tree) is defined to store conditional probabilities of Bayesian network, saving query time compared with traditional Conditional Probability Table (CPT). Experimental results show that a series of strategies proposed by this paper are effective for complex event detection in probabilistic stream.

Last decade has proven a drastic change in information technology. Service Oriented Architecture (SOA), as a new generation of software technique, comes into being to face the challenge of the soaring business varieties and complexities. This paper offers a discussion of service properties and appoints 6 key service properties for SOA. Then, the paper puts forward a role-based reference model for SOA to detail how SOA ensure these properties by service roles and elements. The model is divided into static part and dynamic part: static model describes elements of service roles and files; dynamic model illustrates 6 kinds of interactions between service roles. At last, the paper summarizes the static model, dynamic model and their relationships.