529 research outputs found

    Low-Density Arrays of Circulant Matrices: Rank and Row-Redundancy Analysis, and Quasi-Cyclic LDPC Codes

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    This paper is concerned with general analysis on the rank and row-redundancy of an array of circulants whose null space defines a QC-LDPC code. Based on the Fourier transform and the properties of conjugacy classes and Hadamard products of matrices, we derive tight upper bounds on rank and row-redundancy for general array of circulants, which make it possible to consider row-redundancy in constructions of QC-LDPC codes to achieve better performance. We further investigate the rank of two types of construction of QC-LDPC codes: constructions based on Vandermonde Matrices and Latin Squares and give combinatorial expression of the exact rank in some specific cases, which demonstrates the tightness of the bound we derive. Moreover, several types of new construction of QC-LDPC codes with large row-redundancy are presented and analyzed.Comment: arXiv admin note: text overlap with arXiv:1004.118

    On the Application-Oriented Talents’ Cultivation at Undergraduate Level of Higher Education

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    From the perspective of application-oriented talents’ cultivation at undergraduate level of higher education, the paper describes the connotation, proposes the approach and outlines the general view of cultivating application-oriented talents at undergraduate level of higher education.Key words: Higher education; Undergraduate level; Application-oriented; Talents cultivatin

    Space Adaptation: Privacy-Preserving Multiparty Collaborative Mining with Geometric Perturbation

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    The service-oriented infrastructure has become popular for collaboratively mining data distributed over organizations [3], where the participants are the data providers who submit their perturbed datasets to the designated data mining service provider (the data miner) for mining commonly interested models

    On Social Service Functions of District Universities

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    There have been four functions for nowadays universities: talent cultivation, scientific research, social service and cultural passing and creation. The social service function is the major one among the four because the position of school running, which is to foster application type talents and the role of district economy in social development. The article states the functions, the connotation and the aims of the district universities.Key words: District university; Social service; Connotation; Aim

    Strain Induced One-Dimensional Landau-Level Quantization in Corrugated Graphene

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    Theoretical research has predicted that ripples of graphene generates effective gauge field on its low energy electronic structure and could lead to zero-energy flat bands, which are the analog of Landau levels in real magnetic fields. Here we demonstrate, using a combination of scanning tunneling microscopy and tight-binding approximation, that the zero-energy Landau levels with vanishing Fermi velocities will form when the effective pseudomagnetic flux per ripple is larger than the flux quantum. Our analysis indicates that the effective gauge field of the ripples results in zero-energy flat bands in one direction but not in another. The Fermi velocities in the perpendicular direction of the ripples are not renormalized at all. The condition to generate the ripples is also discussed according to classical thin-film elasticity theory.Comment: 4 figures, Phys. Rev.

    Computational design of steady 3D dissection puzzles

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    Dissection puzzles require assembling a common set of pieces into multiple distinct forms. Existing works focus on creating 2D dissection puzzles that form primitive or naturalistic shapes. Unlike 2D dissection puzzles that could be supported on a tabletop surface, 3D dissection puzzles are preferable to be steady by themselves for each assembly form. In this work, we aim at computationally designing steady 3D dissection puzzles. We address this challenging problem with three key contributions. First, we take two voxelized shapes as inputs and dissect them into a common set of puzzle pieces, during which we allow slightly modifying the input shapes, preferably on their internal volume, to preserve the external appearance. Second, we formulate a formal model of generalized interlocking for connecting pieces into a steady assembly using both their geometric arrangements and friction. Third, we modify the geometry of each dissected puzzle piece based on the formal model such that each assembly form is steady accordingly. We demonstrate the effectiveness of our approach on a wide variety of shapes, compare it with the state-of-the-art on 2D and 3D examples, and fabricate some of our designed puzzles to validate their steadiness

    Identification of dissociation factors in pancreatic Cancer using a mass spectrometry-based proteomic approach

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    Backgroud Pancreatic cancer is a highly malignant tumor of the digestive system. This secretome of pancreatic cancer is key to its progression and metastasis. But different methods of protein extraction affect the final results. In other words, the real secretion of proteins in cancer cells has been changed. Based on mass spectrometry, we analyze the secretome from the serum-containing and serum-free medium, using different protein pretreatment methods. This study aims to identify dissociation factors in pancreatic cancer. Methods In this study, pancreatic cancer cells were cultured in serum-containing or serum-free medium, and the corresponding supernatants were extracted as samples. Subsequently, the above samples were separated by size exclusion chromatography (SEC), and peptide segments were identified by LC-MS/MS. The final results were identified via the hamster secreted protein database and a public database. Results Although the number of identified proteins in the serum-free medium group was high, the real secretion of proteins in pancreatic cancer cells was changed. There were six significant secreted proteins in the serum-containing medium group. Survival analysis via the TCGA database suggested that patients with higher expression levels of YWHAG showed a worse overall survival rate than those with lower YWHAG expression. Conclusions Our study demonstrated the results in the serum-containing medium group were more similar to the real secretome of pancreatic cancer cells. YWHAG could be used as a prognostic indicator for pancreatic cancer

    Research on “Main Classroom+” Practice Teaching Model of Political Theory Courses

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    Essentially, the top priority of political theory teaching reform and innovation in military academies is to fully implement the military education strategies of the new era, and to focus on the fundamental task and core direction characterized by fostering virtue through education and training talents for warfare. In this regard, this paper explores the construction of the “main classroom+” practice teaching model of political theory course from four dimensions, encompassing “thematic practice”, “professional customization”, “comprehensive exercise”, and “practice expansion”, intending to provide feasible paths and methods for military academies to realize more effective integration of theory and practice of political theory teaching in the new era
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