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We investigate the problem of processing a large amount of continuous spatial-keyword queries over streaming data, which is essential in many applications such as locationbased recommendation and advertising, thanks to the proliferation of geo-equipped devices and the ensuing location-based social media applications. For example, a location-based e-coupon system may allow potentially millions of users to register their continuous spatial-keyword queries (e.g., interests in nearby sales) by specifying a set of keywords and a spatial region; the system then delivers each incoming spatial-textual object (e.g., a geo-tagged e-coupon) to all the matched queries (i.e., users) whose spatial and textual requirements are satisfied. While there are several prior approaches aiming at providing efficient query processing techniques for the problem, their approaches belong to spatial-first indexing method which cannot well exploit the keyword distribution. In addition, their textual filtering techniques are built upon simple variants of traditional inverted indexes, which do not perform well for the textual constraint imposed by the problem. In this paper, we address the above limitations and provide a highly efficient solution based on a novel adaptive index, named AP-Tree. The AP-Tree adaptively groups registered queries using keyword and spatial partitions, guided by a cost model. The AP-Tree also naturally indexes ordered keyword combinations. We present index construction algorithm that seamlessly and effectively integrates keyword and spatial partitions. Consequently, our method adapts well to the underlying spatial and keyword distributions of the data. Our extensive experiments demonstrate that AP-Tree achieves up to an order of magnitude improvement on efficiency compared with prior state-of-the-art methods.

Hypertrophy of ligamentum flavum (LF), along with disk protrusion and facet joints degeneration, is associated with the development of lumbar spinal canal stenosis (LSCS). Of note, LF hypertrophy is deemed as an important cause of LSCS. Histologically, fibrosis is proved to be the main pathology of LF hypertrophy. Despite the numerous studies explored the mechanisms of LF fibrosis at the molecular and cellular levels, the exact mechanism remains unknown. It is suggested that pathophysiologic stimuli such as mechanical stress, aging, obesity, and some diseases are the causative factors. Then, many cytokines and growth factors secreted by LF cells and its surrounding tissues play different roles in activating the fibrotic response. Here, we summarize the current status of detailed knowledge available regarding the causative factors, pathology, molecular and cellular mechanisms implicated in LF fibrosis and hypertrophy, also focusing on the possible avenues for anti-fibrotic strategies.

Fault diagnosis is essentially a kind of pattern recognition. The measured signal samples usually distribute on nonlinear low-dimensional manifolds embedded in the high-dimensional signal space, so how to implement feature extraction, dimensionality reduction and improve recognition performance is a crucial task. In this paper a novel machinery fault diagnosis approach based on a statistical locally linear embedding (S-LLE) algorithm which is an extension of LLE by exploiting the fault class label information is proposed. The fault diagnosis approach first extracts the intrinsic manifold features from the high-dimensional feature vectors which are obtained from vibration signals that feature extraction by time-domain, frequency-domain and empirical mode decomposition (EMD), and then translates the complex mode space into a salient low-dimensional feature space by the manifold learning algorithm S-LLE, which outperforms other feature reduction methods such as PCA, LDA and LLE. Finally in the feature reduction space pattern classification and fault diagnosis by classifier are carried out easily and rapidly. Rolling bearing fault signals are used to validate the proposed fault diagnosis approach. The results indicate that the proposed approach obviously improves the classification performance of fault pattern recognition and outperforms the other traditional approaches.

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With the development of Internet, various kinds of new applications appear constantly. They all have high requirements to the time delay, throughput, especially strong real-time applications such as mobile monitoring, video calls. The satellite network in Navigation Satellite System, which is necessary for the mobile monitoring, has many disadvantages such as asymmetric bandwidth, unstable network, high bit error rate and so on. This is a new challenge to the existing congestion control method. In order to improve the performance of congestion control mechanism, we put forward TCP-QS (Quick Start) from the TCP protocol control in this paper. TCP-QS algorithm mainly optimize the slow start stage. At the beginning of the connection, the value of parameter cwnd is set as a larger value according to the detected network bandwidth in which way, the time of the slow start stage is shortened during the transmission, and is adjusted the value of parameter ssthresh dynamically according to the change of network. When packet loss occurs, it takes different methods according to the different reasons.

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A new clustering routing method based on predictive energy consumption efficiency (PECE) for a wireless sensor network (WSN) is presented in this paper. It consists of two stages: cluster formation and stable data transfer. In the cluster formation stage, we design an energy-saving clustering routing algorithm based on the node degree, the relative distance between nodes, and the rest energy of nodes. When this algorithm selects the cluster head, the node degree and the relative distance between the nodes are fully considered, so the selected cluster not only has better coverage performance but also short average distance from other member nodes in the formative cluster; therefore, the cost of communications within the clusters is small. In the stable data transfer stage, by using bee colony optimization (BCO), we design a PECE strategy for data transmission. On the basis of considering the predictive values of energy consumption, the hops, and the propagation delay on this route, this strategy gives a precise definition of the route yield by using two types of bee agent to predict the route yield of each routing path from the source node to the sink node. Through the optimization design of the algorithm, it can improve the quality of clusters, thereby increasing the overall network performance, and reduces and balances the energy consumption of whole network and prolongs the survival time of the network.