686 research outputs found
Classification and enumeration of lattice polygons in a disc
In 1980, V. I. Arnold studied the classification problem for convex lattice
polygons of given area. Since then, this problem and its analogues have been
studied by many authors, including , Lagarias,
Pach, Santos, Ziegler and Zong. Recently, Zong proposed two computer programs
to prove Hadwiger's covering conjecture and Borsuk's partition problem,
respectively, based on enumeration of the convex lattice polytopes contained in
certain balls. For this purpose, similar to
and Pach's work on volume and Liu and Zong's work on cardinality, we obtain
bounds on the number of non-equivalent convex lattice polygons in a given disc.
Furthermore, we propose an algorithm to enumerate these convex lattice
polygons.Comment: 19 pages, 3 figure
Tip induced unconventional superconductivity on Weyl semimetal TaAs
Weyl fermion is a massless Dirac fermion with definite chirality, which has
been long pursued since 1929. Though it has not been observed as a fundamental
particle in nature, Weyl fermion can be realized as low-energy excitation
around Weyl point in Weyl semimetal, which possesses Weyl fermion cones in the
bulk and nontrivial Fermi arc states on the surface. As a firstly discovered
Weyl semimetal, TaAs crystal possesses 12 pairs of Weyl points in the momentum
space, which are topologically protected against small perturbations. Here, we
report for the first time the tip induced superconductivity on TaAs crystal by
point contact spectroscopy. A conductance plateau and sharp double dips are
observed in the point contact spectra, indicating p-wave like unconventional
superconductivity. Furthermore, the zero bias conductance peak in low
temperature regime is detected, suggesting potentially the existence of
Majorana zero modes. The experimentally observed tunneling spectra can be
interpreted with a novel mirror-symmetry protected topological superconductor
induced in TaAs, which can exhibit zero bias and double finite bias peaks, and
double conductance dips in the measurements. Our work can open a broad avenue
in search for new topological superconducting phases from topological Weyl
materials and trigger intensive investigations for pursuing Majorana fermions
KNOWLEDGE TRANSFERRING PATH BASED ON KNOWLEDGE LINK——THE KNOWLEDGE TRANSFER OF SCIENTIFIC AND TECHNOLOGICAL ACHIVEMENTS AS AN EXAMPLE
Scientific and technological achievements which are used in the life become more and more prominent, and
gradually change the people live way. In order to meet the needs of society, it is important do scientific
achievements better, knowledge transfer should be the focus of the current knowledge management. This paper
first clarifies the related concepts of knowledge chain, knowledge transfer, key path, and then shows the basic
connotation of knowledge transfer of scientific and technological achievements, analyzes how scientific and
technological achievements are transformed, and finally establishes the knowledge transfer path model of
scientific and technological achievements. This paper validates the superiority of the model to solve the real
problem, and provides the theoretical basis for the determination of the scientific and technological achievements
into the key path of the real product, and has certain practical significance
コーパス ニ モトズイタ コロケーション ブンセキ : ステキ リッパ スバラシイ オ レイ ニ
国語研とLago言語研究所が共同開発した『NLB』コーパスを用いて類義語である「素敵」「立派」「素晴らしい」のコロケーションの情報を抽出して異同について調査を行った。本研究では、調査結果を基に学習者にとって必要と思われる「素敵」「立派」「素晴らしい」のコロケーション情報についての試案を述べる
Technology Forecasting based on Topic Analysis and Social Network Analysis: A Case Study Focusing on Gene Editing Patents
Technology forecasting research is an indispensable means to master the development trend of technology and provide decision support for scientific research management. For patent documents, it does not provide keyword information, which makes the keyword based technology prediction method have some limitations in revealing research content and hidden topics in specific fields. In order to better reflect the technical information in the patent, this paper combines topic analysis and social network analysis to study the development trends of gene editing technology. First, the patent data of gene editing technology is collected from Derwent Innovations Index. Secondly, text mining software is adopted to draw a network graph of topic words, combined with Inverse Document Frequency (IDF) to construct a weighted adjacency matrix, and Social Network Analysis is used to obtain the degree of centrality of technical topic words. Finally, the technological trends of gene editing technology is explored by identifying the core themes of gene editing, highlighting themes and emerging themes, and some meaningful conclusions are also obtained. Based on the analysis results, this study finds that the development of gene editing technology is limited by factors such as ethics, law and cellular pollution. In addition, future research directions will be more inclined to optimize the safety and efficiency of gene editing technology.
Technology Forecasting based on Topic Analysis and Social Network Analysis: A Case Study Focusing on Gene Editing Patents
428-437Technology forecasting research is an indispensable means to master the development trend of technology and provide decision support for scientific research management. For patent documents, it does not provide keyword information, which makes the keyword based technology prediction method have some limitations in revealing research content and hidden topics in specific fields. In order to better reflect the technical information in the patent, this paper combines topic analysis and social network analysis to study the development trends of gene editing technology. First, the patent data of gene editing technology is collected from Derwent Innovations Index. Secondly, text mining software is adopted to draw a network graph of topic words, combined with Inverse Document Frequency (IDF) to construct a weighted adjacency matrix, and Social Network Analysis is used to obtain the degree of centrality of technical topic words. Finally, the technological trends of gene editing technology is explored by identifying the core themes of gene editing, highlighting themes and emerging themes, and some meaningful conclusions are also obtained. Based on the analysis results, this study finds that the development of gene editing technology is limited by factors such as ethics, law and cellular pollution. In addition, future research directions will be more inclined to optimize the safety and efficiency of gene editing technology
Deep Learning Overloaded Vehicle Identification for Long Span Bridges Based on Structural Health Monitoring Data
Overloaded vehicles bring great harm to transportation infrastructures. BWIM
(bridge weigh-in-motion) method for overloaded vehicle identification is
getting more popular because it can be implemented without interruption to the
traffic. However, its application is still limited because its effectiveness
largely depends on professional knowledge and extra information, and is
susceptible to occurrence of multiple vehicles. In this paper, a deep learning
based overloaded vehicle identification approach (DOVI) is proposed, with the
purpose of overloaded vehicle identification for long-span bridges by the use
of structural health monitoring data. The proposed DOVI model uses temporal
convolutional architectures to extract the spatial and temporal features of the
input sequence data, thus provides an end-to-end overloaded vehicle
identification solution which neither needs the influence line nor needs to
obtain velocity and wheelbase information in advance and can be applied under
the occurrence of multiple vehicles. Model evaluations are conducted on a
simply supported beam and a long-span cable-stayed bridge under random traffic
flow. Results demonstrate that the proposed deep-learning overloaded vehicle
identification approach has better effectiveness and robustness, compared with
other machine learning and deep learning approaches
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