23 research outputs found

    The Exploration and Practice of the Construction of Civic Politics in Computer Science Courses under the Perspective of “Three-Whole Education”

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    Taking the computer application technology professional group of Guangdong Innovation Technology College as an example, we study the problems of computer professional group in the construction of curriculum thinking politics, firstly, we explore the basic requirements of curriculum thinking politics from the perspective of “ Three-Whole Education “, then we explore the value of curriculum thinking politics, and then we study the top design and bottom implementation of talent training of professional group from many aspects. Then, we will explore the value of curriculum thinking and politics, and then carry out research from various aspects such as top-level design and bottom-level implementation of professional group talent training. We will build the construction pattern of “Three-Whole Education”, and combine with the construction of professional groups to build the construction pattern of the curriculum of professional groups in terms of talent training objectives, thinking and political objectives, thinking and political content, etc., so as to promote the construction of the curriculum of the provincial-level professional group of computer application technology in our university and realize the educational goal of cultivating people with moral character

    Dynamical SimRank search on time-varying networks

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    SimRank is an appealing pair-wise similarity measure based on graph structure. It iteratively follows the intuition that two nodes are assessed as similar if they are pointed to by similar nodes. Many real graphs are large, and links are constantly subject to minor changes. In this article, we study the efficient dynamical computation of all-pairs SimRanks on time-varying graphs. Existing methods for the dynamical SimRank computation [e.g., LTSF (Shao et al. in PVLDB 8(8):838–849, 2015) and READS (Zhang et al. in PVLDB 10(5):601–612, 2017)] mainly focus on top-k search with respect to a given query. For all-pairs dynamical SimRank search, Li et al.’s approach (Li et al. in EDBT, 2010) was proposed for this problem. It first factorizes the graph via a singular value decomposition (SVD) and then incrementally maintains such a factorization in response to link updates at the expense of exactness. As a result, all pairs of SimRanks are updated approximately, yielding (Formula presented.) time and (Formula presented.) memory in a graph with n nodes, where r is the target rank of the low-rank SVD. Our solution to the dynamical computation of SimRank comprises of five ingredients: (1) We first consider edge update that does not accompany new node insertions. We show that the SimRank update (Formula presented.) in response to every link update is expressible as a rank-one Sylvester matrix equation. This provides an incremental method requiring (Formula presented.) time and (Formula presented.) memory in the worst case to update (Formula presented.) pairs of similarities for K iterations. (2) To speed up the computation further, we propose a lossless pruning strategy that captures the “affected areas” of (Formula presented.) to eliminate unnecessary retrieval. This reduces the time of the incremental SimRank to (Formula presented.), where m is the number of edges in the old graph, and (Formula presented.) is the size of “affected areas” in (Formula presented.), and in practice, (Formula presented.). (3) We also consider edge updates that accompany node insertions, and categorize them into three cases, according to which end of the inserted edge is a new node. For each case, we devise an efficient incremental algorithm that can support new node insertions and accurately update the affected SimRanks. (4) We next study batch updates for dynamical SimRank computation, and design an efficient batch incremental method that handles “similar sink edges” simultaneously and eliminates redundant edge updates. (5) To achieve linear memory, we devise a memory-efficient strategy that dynamically updates all pairs of SimRanks column by column in just (Formula presented.) memory, without the need to store all (Formula presented.) pairs of old SimRank scores. Experimental studies on various datasets demonstrate that our solution substantially outperforms the existing incremental SimRank methods and is faster and more memory-efficient than its competitors on million-scale graphs

    SimRank*: effective and scalable pairwise similarity search based on graph topology

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    Given a graph, how can we quantify similarity between two nodes in an effective and scalable way? SimRank is an attractive measure of pairwise similarity based on graph topologies. Its underpinning philosophy that “two nodes are similar if they are pointed to (have incoming edges) from similar nodes” can be regarded as an aggregation of similarities based on incoming paths. Despite its popularity in various applications (e.g., web search and social networks), SimRank has an undesirable trait, i.e., “zero-similarity”: it accommodates only the paths of equal length from a common “center” node, whereas a large portion of other paths are fully ignored. In this paper, we propose an effective and scalable similarity model, SimRank*, to remedy this problem. (1) We first provide a sufficient and necessary condition of the “zero-similarity” problem that exists in Jeh and Widom’s SimRank model, Li et al. ’s SimRank model, Random Walk with Restart (RWR), and ASCOS++. (2) We next present our treatment, SimRank*, which can resolve this issue while inheriting the merit of the simple SimRank philosophy. (3) We reduce the series form of SimRank* to a closed form, which looks simpler than SimRank but which enriches semantics without suffering from increased computational overhead. This leads to an iterative form of SimRank*, which requires O(Knm) time and O(n2) memory for computing all (n2) pairs of similarities on a graph of n nodes and m edges for K iterations. (4) To improve the computational time of SimRank* further, we leverage a novel clustering strategy via edge concentration. Due to its NP-hardness, we devise an efficient heuristic to speed up all-pairs SimRank* computation to O(Knm~) time, where m~ is generally much smaller than m. (5) To scale SimRank* on billion-edge graphs, we propose two memory-efficient single-source algorithms, i.e., ss-gSR* for geometric SimRank*, and ss-eSR* for exponential SimRank*, which can retrieve similarities between all n nodes and a given query on an as-needed basis. This significantly reduces the O(n2) memory of all-pairs search to either O(Kn+m~) for geometric SimRank*, or O(n+m~) for exponential SimRank*, without any loss of accuracy, where m~â‰Șn2 . (6) We also compare SimRank* with another remedy of SimRank that adds self-loops on each node and demonstrate that SimRank* is more effective. (7) Using real and synthetic datasets, we empirically verify the richer semantics of SimRank*, and validate its high computational efficiency and scalability on large graphs with billions of edges

    The Exploration and Practice of the Construction of Civic Politics in Computer Science Courses under the Perspective of “Three-Whole Education”

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    Taking the computer application technology professional group of Guangdong Innovation Technology College as an example, we study the problems of computer professional group in the construction of curriculum thinking politics, firstly, we explore the basic requirements of curriculum thinking politics from the perspective of “ Three-Whole Education “, then we explore the value of curriculum thinking politics, and then we study the top design and bottom implementation of talent training of professional group from many aspects. Then, we will explore the value of curriculum thinking and politics, and then carry out research from various aspects such as top-level design and bottom-level implementation of professional group talent training. We will build the construction pattern of “Three-Whole Education”, and combine with the construction of professional groups to build the construction pattern of the curriculum of professional groups in terms of talent training objectives, thinking and political objectives, thinking and political content, etc., so as to promote the construction of the curriculum of the provincial-level professional group of computer application technology in our university and realize the educational goal of cultivating people with moral character

    Online soft sensor design using local partial least squares models with adaptive process state partition

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    We propose a soft sensing method using local partial least squares models with adaptive process state partition, referring to as the LPLS-APSP, which is capable of effectively handling time-varying characteristics and nonlinearities of processes, the two major adverse effects of common industrial processes that cause low-performance of soft sensors. In our proposed approach, statistical hypothesis testing is employed to adaptively partition the process state into the unique local model regions each consisting of certain number of consecutive-time data samples, and partial least squares is adopted to construct local models. Advantages of this adaptive strategy are that the number of local models does not need to be pre-defined and the local model set can be augmented online without retraining from scratch. Moreover, to improve the prediction accuracy, a novel online model adaptation criterion is proposed, which not only takes the current process dynamics into account, but also enables mining the information contained in the neighborhood of the query sample. The guidelines for tuning the model parameters are also presented. The LPLS-APSP scheme is applied to develop the dynamic soft sensors for a simulated continuous stirred tank reactor and a real industrial debutanizer column, and the results obtained demonstrate the effectiveness of this proposed approach, in comparison to several existing state-of-the-art methods, for online soft sensor desig

    Genome-Wide Survey Reveals Transcriptional Differences Underlying the Contrasting Trichome Phenotypes of Two Sister Desert Poplars

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    Trichomes, which are widely used as an important diagnostic characteristic in plant species delimitation, play important roles in plant defense and adaptation to adverse environments. In this study, we used two sister poplar species, Populus pruinosa and Populus euphratica—which have, respectively, dense and sparse trichomes—to examine the genetic differences associated with these contrasting phenotypes. The results showed that 42 and 45 genes could be identified as candidate genes related to trichomes in P. pruinosa and P. euphratica, respectively; most of these genes possessed high degrees of diversification in their coding sequences, but they were similar in intron/exon structure in the two species. We also found that most of the candidate trichome genes were expressed at higher levels in P. pruinosa, which has dense trichomes, than in P. euphratica, where there are few trichomes. Based on analyses of transcriptional profiles, a total of 195 genes, including many transcription factors, were found to show distinct differences in expression. The results of gene function annotation suggested that the genes identified as having contrasting levels of expression level are mainly associated with trichome elongation, ATPase activity, and hormone transduction. Changes in the expression of these and other related genes with high sequence diversification may have contributed to the contrast in the pattern of trichome phenotypes between the two species

    Tissue-Specific Transcriptome Analysis Reveals Multiple Responses to Salt Stress in Populus euphratica Seedlings

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    Salt stress is one of the most crucial factors impacting plant growth, development and reproduction. However, information regarding differences in tissue-specific gene expression patterns, which may improve a plant’s tolerance to salt stress, is limited. Here, we investigated the gene expression patterns in tissues of Populus euphratica Oliv. seedlings using RNA sequencing (RNA-Seq) technology. A total of 109.3 million, 125bp paired-end clean reads were generated, and 6428, 4797, 2335 and 3358 differentially expressed genes (DEGs) were identified in leaf, phloem, xylem and root tissues, respectively. While the tissue-specific DEGs under salt stress had diverse functions, “membrane transporter activity” was the most significant leaf function, whereas “oxidation–reduction process” was the most significant function in root tissue. Further analysis of the tissue-specific DEGs showed that the expression patterns or functions of gene families, such as SOS, NHX, GolS, GPX, APX, RBOHF and CBL, were diverse, suggesting that calcium signaling, reactive oxygen species (ROS) and salt overly sensitive (SOS) pathways are all involved in ionic homeostasis in tissues from P. euphratica seedlings. The DEGs, for example the up-regulated antioxidant genes, contribute to ROS-scavenging induced by salt stress but result in decreased Na+ concentrations in root vasculature cells and in xylem sap, while the down-regulated rbohF leads to the reverse results. These results suggest that the divergence of DEGs expression patterns contribute to maintenance of ionic and ROS homeostasis in tissues and improve plant salinity tolerance. We comprehensively analyzed the response of P. euphratica seedlings to salt stress and provide helpful genetic resources for studying plant-abiotic stress interactions
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