Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province

China

Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province

China
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Gong F.,China University of Petroleum - East China | Shao M.-W.,China University of Petroleum - East China | Shao M.-W.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province | Qiu G.,Shanxi University
International Journal of Machine Learning and Cybernetics | Year: 2017

In this paper, three kinds of adjoint extent-intent and intent-extent operators between two complete lattices are constructed. Three new types of concept granular computing systems are then formulated via a quadruple including two complete lattices and the corresponding adjoint operators. It is showed that all the concepts in any of the concept granular computing systems form a complete lattice. Furthermore, based on the four types of concept granular computing systems, we present four types of rough set approximation operators in a formal context which can characterize different aspect of knowledge. Some important properties of the proposed approximation operators are also proved. © 2015, Springer-Verlag Berlin Heidelberg.


Yang X.,Zhejiang Ocean University | Yang X.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province | Tan A.,Zhejiang Ocean University | Tan A.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2017

The intuitionistic fuzzy set is introduced to incomplete information systems, in which the membership and non-membership degrees that an object belongs to a concept are constructed by the rough set approximations based on similarity relation. Then, by combining the intuitionistic fuzzy set and three-way decisions, we proposed two evaluation functions to generate decision rules and make three-way decisions in incomplete information systems. © Springer International Publishing AG 2017.


Li K.,China University of Petroleum - East China | Shao M.-W.,China University of Petroleum - East China | Wu W.-Z.,Zhejiang Ocean University | Wu W.-Z.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province
International Journal of Machine Learning and Cybernetics | Year: 2017

As a basic operation in data mining and knowledge discovery, data reduction can reduce the volume of the data and simplify the representation of knowledge. In this paper we propose a method of attribute reduction in a formal fuzzy context based on the notion of “one-sided fuzzy concept”. According to the importance of attributes, we classify the attributes into three types: core attributes, relatively necessary attributes and unnecessary attributes, which are also referred to the attribute characteristics. We propose judgment theorems and the corresponding algorithms for computing the three types of attribute sets. Moreover, a straightforward attribute reduction method by virtue of attribute characteristics is formulated. We show that the computation of formal concepts on the reduced data set is made more efficient, and yet produces the same lattice structure and conceptual hierarchy as the ones derived from the original formal context. © 2016, Springer-Verlag Berlin Heidelberg.


Cheng X.-P.,Zhejiang Ocean University | Cheng X.-P.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province | Wang J.-Y.,Quzhou University | Ren B.,Shaoxing University | And 2 more authors.
Communications in Theoretical Physics | Year: 2016

The consistent tanh expansion (CTE) method is employed to the (2+1)-dimensional Caudrey - Dodd - Gibbon-Kotera - Sawada (CDGKS) equation. The interaction solutions between solitons and the cnoidal periodic waves are explicitly obtained. Concretely, we discuss a special kind of interaction solution in the form of tanh functions and Jacobian elliptic functions in both analytical and graphical ways. The results show that the profiles of the soliton-cnoidal periodic wave interaction solutions can be designed by choosing different values of wave parameters. © 2016 Chinese Physical Society and IOP Publishing Ltd.


Tan A.,Zhejiang Ocean University | Tan A.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province | Wu W.-Z.,Zhejiang Ocean University | Wu W.-Z.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province | Tao Y.,Zhejiang Ocean University
International Journal of Approximate Reasoning | Year: 2017

Multigranulation spaces provide a unified framework for representing multigranulation knowledge. In this paper, we aim to construct belief structures and characterize knowledge reduction in terms of evidence theory for the multigranulation spaces where decision attributes are considered. First, we introduce a type-1 belief structure for a multigranulation space, and prove that a pair of lower and upper pessimistic multigranulation approximations correspond to a pair of belief and plausibility functions under this belief structure. Second, we point out that no belief structure can be induced when using the optimistic multigranulation approximations in general. By adding a special sufficient condition, a second type of belief structure is further explored to study those that cannot be induced. Third, we develop several measurements by using the belief and plausibility functions, and characterize knowledge reduction of multigranulation spaces based on these measurements. In the end, a numerical algorithm for reducing redundant granular structures in multigranulation spaces is designed. An example is used to examine the efficiency of the proposed algorithm. © 2017 Elsevier Inc.


Ren B.,Shaoxing University | Cheng X.-P.,Zhejiang Ocean University | Cheng X.-P.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province | Lin J.,Zhejiang Normal University
Nonlinear Dynamics | Year: 2016

The nonlocal symmetries for the (Formula presented.)-dimensional Konopelchenko–Dubrovsky equation are obtained with the truncated Painlevé method and the Möbious (conformal) invariant form. The nonlocal symmetries are localized to the Lie point symmetries by introducing auxiliary dependent variables. The finite symmetry transformations are obtained by solving the initial value problem of the prolonged systems. The multi-solitary wave solution is presented with the finite symmetry transformations of a trivial solution. In the meanwhile, symmetry reductions in the enlarged systems are studied by the Lie point symmetry approach. Many explicit interaction solutions between solitons and cnoidal periodic waves are discussed both in analytical and in graphical ways. © 2016 Springer Science+Business Media Dordrecht


Li D.,Zhejiang Ocean University | Li D.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province
Information Sciences | Year: 2015

In this paper, we mainly investigate T-extension operations of any t-norms and t-conorms on type-2 fuzzy sets' truth values F2 (a set of all functions defined from [0,1] into itself). Based on it, we first construct some type-2 t-norms on the fuzzy truth values F2 with the ordinary partial order ≤ and the partial order ⊂, respectively. The algebraic properties of these type-2 t-norms are then studied. Moreover, the residual operators of some special type-2 t-norms on (F2,≤) and (F2,⊂) are respectively represented. Finally, we briefly discuss the compositional rule of inference based on type-2 t-norms and their residual operators. © 2015 Elsevier Inc. All rights reserved.


Tan A.,Zhejiang Ocean University | Tan A.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province | Wu W.,Zhejiang Ocean University | Tao Y.,Zhejiang Ocean University
Soft Computing | Year: 2016

In data mining application, the test-cost-sensitive attribute reduction is an important task which aims to decrease the test cost of data. In operational research, the set cover problem is a typical optimization problem and has a long investigation history compared to the attribute reduction problem. In this paper, we employ the methods of set cover problem to deal with the test-cost-sensitive attribute reduction. First, we equivalently transform the test-cost-sensitive reduction problem into the set cover problem by using a constructive approach. It is shown that computing a reduct of a decision system with minimal test cost is equal to computing an optimal solution of the set cover problem. Then, a set-cover-based heuristic algorithm is introduced to solve the test-cost-sensitive reduction problem. In the end, we conduct several numerical experiments on data sets from UCI machine learning repository. Experimental results indicate that the set-cover-based algorithm has superior performances in most cases, and the algorithm is efficient on data sets with many attributes. © 2016 Springer-Verlag Berlin Heidelberg


Yang Y.,Zhejiang Ocean University | Yang Y.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province | Yan Z.,CAS Academy of Mathematics and Systems Science | Malomed B.A.,Tel Aviv University
Chaos | Year: 2015

We analytically study rogue-wave (RW) solutions and rational solitons of an integrable fifth-order nonlinear Schrödinger (FONLS) equation with three free parameters. It includes, as particular cases, the usual NLS, Hirota, and Lakshmanan-Porsezian-Daniel equations. We present continuous-wave (CW) solutions and conditions for their modulation instability in the framework of this model. Applying the Darboux transformation to the CW input, novel first- and second-order RW solutions of the FONLS equation are analytically found. In particular, trajectories of motion of peaks and depressions of profiles of the first- and second-order RWs are produced by means of analytical and numerical methods. The solutions also include newly found rational and W-shaped one- and two-soliton modes. The results predict the corresponding dynamical phenomena in extended models of nonlinear fiber optics and other physically relevant integrable systems. © 2015 AIP Publishing LLC.


Chen Z.,Iowa State University | Huang H.,Zhejiang Ocean University | Huang H.,Key Laboratory of Oceanographic Big Data Mining and Application of Zhejiang Province | Yan J.,Iowa State University
Journal of Computational Physics | Year: 2016

We develop 3rd order maximum-principle-satisfying direct discontinuous Galerkin methods [8,9,19,21] for convection diffusion equations on unstructured triangular mesh. We carefully calculate the normal derivative numerical flux across element edges and prove that, with proper choice of parameter pair (β0, β1) in the numerical flux formula, the quadratic polynomial solution satisfies strict maximum principle. The polynomial solution is bounded within the given range and third order accuracy is maintained. There is no geometric restriction on the meshes and obtuse triangles are allowed in the partition. A sequence of numerical examples are carried out to demonstrate the accuracy and capability of the maximum-principle-satisfying limiter. © 2015 Elsevier Inc.

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