In the present study,we extend the order-preserving(OP)criterion proposed in our latest studies to the WENO-Z-type schemes.Firstly,we innovatively present the concept of the generalized mapped WENO schemes by rewritin...In the present study,we extend the order-preserving(OP)criterion proposed in our latest studies to the WENO-Z-type schemes.Firstly,we innovatively present the concept of the generalized mapped WENO schemes by rewriting the Ztype weights in a uniform formula from the perspective of the mapping relation.Then,we naturally introduce the OP criterion to improve the WENO-Z-type schemes,and the resultant schemes are denoted as MOP-GMWENO-X,where the notation“X”is used to identify the version of the existing WENO-Z-type scheme in this paper.Finally,extensive numerical experiments have been conducted to demonstrate the benefits of these new schemes.We draw the conclusion that,the convergence properties of the proposed schemes are equivalent to the corresponding WENO-X schemes.The major benefit of the new schemes is that they have the capacity to achieve high resolutions and simultaneously remove spurious oscillations for long simulations.The new schemes have the additional benefit that they can greatly decrease the post-shock oscillations on solving 2D Euler problems with strong shock waves.展开更多
Order-preserving submatrix (OPSM) has become important in modelling biologically meaningful subspace cluster, capturing the general tendency of gene expressions across a subset of conditions. With the advance of mic...Order-preserving submatrix (OPSM) has become important in modelling biologically meaningful subspace cluster, capturing the general tendency of gene expressions across a subset of conditions. With the advance of microarray and analysis techniques, big volume of gene expression datasets and OPSM mining results are produced. OPSM query can efficiently retrieve relevant OPSMs from the huge amount of OPSM datasets. However, improving OPSM query relevancy remains a difficult task in real life exploratory data analysis processing. First, it is hard to capture subjective interestingness aspects, e.g., the analyst's expectation given her/his domain knowledge. Second, when these expectations can be declaratively specified, it is still challenging to use them during the computational process of OPSM queries. With the best of our knowledge, existing methods mainly fo- cus on batch OPSM mining, while few works involve OPSM query. To solve the above problems, the paper proposes two constrained OPSM query methods, which exploit userdefined constraints to search relevant results from two kinds of indices introduced. In this paper, extensive experiments are conducted on real datasets, and experiment results demonstrate that the multi-dimension index (cIndex) and enumerating sequence index (esIndex) based queries have better performance than brute force search.展开更多
This paper discusses the order-preserving convergence for spectral approximation of the self-adjoint completely continuous operator T.Under the condition that the approximate operator Th converges to T in norm,it is p...This paper discusses the order-preserving convergence for spectral approximation of the self-adjoint completely continuous operator T.Under the condition that the approximate operator Th converges to T in norm,it is proven that the k-th eigenvalue of Th converges to the k-th eigenvalue of T.(We sorted the positive eigenvalues in decreasing order and negative eigenvalues in increasing order.) Then we apply this result to conforming elements,nonconforming elements and mixed elements of self-adjoint elliptic differential operators eigenvalue problems,and prove that the k-th approximate eigenvalue obtained by these methods converges to the k-th exact eigenvalue.展开更多
For n E N, let On be the semigroup of all singular order-preserving mappings on [n] = (1, 2,..., n}. For each nonempty subset A of [n], let On (A) = (a ∈ On: (A k ∈ A) ka ≤ k} be the semigroup of all order-p...For n E N, let On be the semigroup of all singular order-preserving mappings on [n] = (1, 2,..., n}. For each nonempty subset A of [n], let On (A) = (a ∈ On: (A k ∈ A) ka ≤ k} be the semigroup of all order-preserving and A-decreasing mappings on [n]. In this paper it is shown that On(A)is an abundant semigroup with n - 1 *-classes. Moreover, On(A) is idempotent-generated and its idempotent rank is 2n - 2 - IA/(n}l. Further, it is shown that the rank of On(A) is equal to n - 1 if 1 ∈ A, and it is equal to n otherwise.展开更多
This work is concerned with coupling for a class of Markovian switching jump-diffusion processes.The processes under consideration can be regarded as a number of jump-diffusion processes modulated by a Markovian switc...This work is concerned with coupling for a class of Markovian switching jump-diffusion processes.The processes under consideration can be regarded as a number of jump-diffusion processes modulated by a Markovian switching device.For this class of processes,we construct a successful coupling and an order-preserving coupling.展开更多
In this paper,we first show that for a Banach space X,there is a fully order-reversing mapping T from conv(X)(the cone of all the extended real-valued lower semicontinuous proper convex functions defined on X)onto its...In this paper,we first show that for a Banach space X,there is a fully order-reversing mapping T from conv(X)(the cone of all the extended real-valued lower semicontinuous proper convex functions defined on X)onto itself if and only if X is reflexive and linearly isomorphic to its dual X^(*).Then we further prove the following generalized Artstein-Avidan-Milman representation theorem:For every fully order-reversing mapping T:conv(X)→conv(X),there exist a linear isomorphism U:X→X^(*),x_(0)^(*),φ_(0)∈X^(*),α>0 and r_0∈R so that(Tf)(x)=α(Ff)(Ux+x_(0)^(*))+<φ_(0),x>+r_(0),■x∈X where T:conv(X)→conv(X^(*))is the Fenchel transform.Hence,these resolve two open questions.We also show several representation theorems of fully order-preserving mappings defined on certain cones of convex functions.For example,for every fully order-preserving mapping S:semn(X)→semn(X),there is a linear isomorphism U:X→X so that(Sf)(x)=f(Ux),■f∈semn(X),x∈X where semn(X)is the cone of all the lower semicontinuous seminorms on X.展开更多
Order-preserving encryption(OPE)and order-revealing encryption(ORE)are among the core ingredients for encrypted databases(EDBs).In this work,we study the leakage of OPE and ORE and their forward security.We propose ge...Order-preserving encryption(OPE)and order-revealing encryption(ORE)are among the core ingredients for encrypted databases(EDBs).In this work,we study the leakage of OPE and ORE and their forward security.We propose generic yet powerful file-inject ion attacks(FI As)on OPE/ORE,aimed at the situations of possessing order by and range queries.Our FI As only exploit the ideal leakage of OPE/ORE(in particular,no need of data denseness or frequency).We also improve their efficiency with the frequency statistics using a hierarchical idea such that the high-frequency values will be recovered more quickly.We conduct some experiments on real datasets to test the performance,and the results show that our FI As can cause an extreme hazard on most of the existing OPEs and OREs with high efficiency and 100%recovery rate.We then formulate forward security of ORE,and propose a practical compilation framework for achieving forward secure ORE to resist the perniciousness of FIA.The compilation framework can transform most of the existing OPEs/OREs into forward secure OREs,with the goal of minimizing the extra burden incurred on computation and storage.We also present its security proof,and execute some experiments to analyze its performance.The proposed compilation is highly efficient and forward secure.展开更多
A new type offinite volume WENO schemes for hyperbolic problems was devised in[33]by introducing the order-preserving(OP)criterion.In this continuing work,we extend the OP criterion to the WENO-Z-type schemes.Wefirstl...A new type offinite volume WENO schemes for hyperbolic problems was devised in[33]by introducing the order-preserving(OP)criterion.In this continuing work,we extend the OP criterion to the WENO-Z-type schemes.Wefirstly rewrite the formulas of the Z-type weights in a uniform form from a mapping perspective inspired by extensive numerical observations.Accordingly,we build the concept of the locally order-preserving(LOP)mapping which is an extension of the order-preserving(OP)mapping and the resultant improved WENO-Z-type schemes are denoted as LOP-GMWENO-X.There are four major advantages of the LOP-GMWENO-X schemes superior to the existing WENO-Z-type schemes.Firstly,the new schemes can amend the serious drawback of the existing WENO-Z-type schemes that most of them suffer from either producing severe spurious oscillations or failing to obtain high resolutions in long calculations of hyperbolic problems with discontinuities.Secondly,they can maintain considerably high resolutions on solving problems with high-order critical points at long output times.Thirdly,they can obtain evidently higher resolution in the region with high-frequency but smooth waves.Finally,they can significantly decrease the post-shock oscillations for simulations of some 2D problems with strong shock waves.Extensive benchmark examples are conducted to illustrate these advantages.展开更多
文摘In the present study,we extend the order-preserving(OP)criterion proposed in our latest studies to the WENO-Z-type schemes.Firstly,we innovatively present the concept of the generalized mapped WENO schemes by rewriting the Ztype weights in a uniform formula from the perspective of the mapping relation.Then,we naturally introduce the OP criterion to improve the WENO-Z-type schemes,and the resultant schemes are denoted as MOP-GMWENO-X,where the notation“X”is used to identify the version of the existing WENO-Z-type scheme in this paper.Finally,extensive numerical experiments have been conducted to demonstrate the benefits of these new schemes.We draw the conclusion that,the convergence properties of the proposed schemes are equivalent to the corresponding WENO-X schemes.The major benefit of the new schemes is that they have the capacity to achieve high resolutions and simultaneously remove spurious oscillations for long simulations.The new schemes have the additional benefit that they can greatly decrease the post-shock oscillations on solving 2D Euler problems with strong shock waves.
基金The authors thank the anonymous referees for their useful comments that greatly improved the quality of the paper. This work was supported in part by the National Basic Research Program 973 of China (2012CB316203), the Natural Science Foundation of China (Grant Nos. 61033007, 61272121, 61332014, 61572367, 61332006, 61472321, and 61502390), the National High Technology Research and Development Program 863 of China (2015AA015307), the Fundational Research Funds for the Central Universities (3102015JSJ0011, 3102014JSJ0005, and 3102014JSJ0013), and the Graduate Starting Seed Fund of Northwestern Polytechnical University (Z2012128).
文摘Order-preserving submatrix (OPSM) has become important in modelling biologically meaningful subspace cluster, capturing the general tendency of gene expressions across a subset of conditions. With the advance of microarray and analysis techniques, big volume of gene expression datasets and OPSM mining results are produced. OPSM query can efficiently retrieve relevant OPSMs from the huge amount of OPSM datasets. However, improving OPSM query relevancy remains a difficult task in real life exploratory data analysis processing. First, it is hard to capture subjective interestingness aspects, e.g., the analyst's expectation given her/his domain knowledge. Second, when these expectations can be declaratively specified, it is still challenging to use them during the computational process of OPSM queries. With the best of our knowledge, existing methods mainly fo- cus on batch OPSM mining, while few works involve OPSM query. To solve the above problems, the paper proposes two constrained OPSM query methods, which exploit userdefined constraints to search relevant results from two kinds of indices introduced. In this paper, extensive experiments are conducted on real datasets, and experiment results demonstrate that the multi-dimension index (cIndex) and enumerating sequence index (esIndex) based queries have better performance than brute force search.
基金supported by the National Natural Science Foundation of China (Grant No. 10761003)Guizhou Province Scientific Research for Senior Personnels
文摘This paper discusses the order-preserving convergence for spectral approximation of the self-adjoint completely continuous operator T.Under the condition that the approximate operator Th converges to T in norm,it is proven that the k-th eigenvalue of Th converges to the k-th eigenvalue of T.(We sorted the positive eigenvalues in decreasing order and negative eigenvalues in increasing order.) Then we apply this result to conforming elements,nonconforming elements and mixed elements of self-adjoint elliptic differential operators eigenvalue problems,and prove that the k-th approximate eigenvalue obtained by these methods converges to the k-th exact eigenvalue.
文摘For n E N, let On be the semigroup of all singular order-preserving mappings on [n] = (1, 2,..., n}. For each nonempty subset A of [n], let On (A) = (a ∈ On: (A k ∈ A) ka ≤ k} be the semigroup of all order-preserving and A-decreasing mappings on [n]. In this paper it is shown that On(A)is an abundant semigroup with n - 1 *-classes. Moreover, On(A) is idempotent-generated and its idempotent rank is 2n - 2 - IA/(n}l. Further, it is shown that the rank of On(A) is equal to n - 1 if 1 ∈ A, and it is equal to n otherwise.
基金Supported by the National Natural Science Foundation of China (11171024)
文摘This work is concerned with coupling for a class of Markovian switching jump-diffusion processes.The processes under consideration can be regarded as a number of jump-diffusion processes modulated by a Markovian switching device.For this class of processes,we construct a successful coupling and an order-preserving coupling.
基金supported by National Natural Science Foundation of China(Grant Nos.11731010 and 11371296)。
文摘In this paper,we first show that for a Banach space X,there is a fully order-reversing mapping T from conv(X)(the cone of all the extended real-valued lower semicontinuous proper convex functions defined on X)onto itself if and only if X is reflexive and linearly isomorphic to its dual X^(*).Then we further prove the following generalized Artstein-Avidan-Milman representation theorem:For every fully order-reversing mapping T:conv(X)→conv(X),there exist a linear isomorphism U:X→X^(*),x_(0)^(*),φ_(0)∈X^(*),α>0 and r_0∈R so that(Tf)(x)=α(Ff)(Ux+x_(0)^(*))+<φ_(0),x>+r_(0),■x∈X where T:conv(X)→conv(X^(*))is the Fenchel transform.Hence,these resolve two open questions.We also show several representation theorems of fully order-preserving mappings defined on certain cones of convex functions.For example,for every fully order-preserving mapping S:semn(X)→semn(X),there is a linear isomorphism U:X→X so that(Sf)(x)=f(Ux),■f∈semn(X),x∈X where semn(X)is the cone of all the lower semicontinuous seminorms on X.
基金the National Key Research and Development Program of China under Grant No.2017YFB-0802000the National Natural Science Foundation of China under Grant Nos.61472084 and U1536205+2 种基金Shanghai Innovation Action Project under Grant No.16DZ1100200Shanghai Science and Technology Development Funds under Grant No.16JC1400801Shandong Provincial Key Research and Development Program of China under Grant Nos.2017CXG0701 and 2018CXGC0701.
文摘Order-preserving encryption(OPE)and order-revealing encryption(ORE)are among the core ingredients for encrypted databases(EDBs).In this work,we study the leakage of OPE and ORE and their forward security.We propose generic yet powerful file-inject ion attacks(FI As)on OPE/ORE,aimed at the situations of possessing order by and range queries.Our FI As only exploit the ideal leakage of OPE/ORE(in particular,no need of data denseness or frequency).We also improve their efficiency with the frequency statistics using a hierarchical idea such that the high-frequency values will be recovered more quickly.We conduct some experiments on real datasets to test the performance,and the results show that our FI As can cause an extreme hazard on most of the existing OPEs and OREs with high efficiency and 100%recovery rate.We then formulate forward security of ORE,and propose a practical compilation framework for achieving forward secure ORE to resist the perniciousness of FIA.The compilation framework can transform most of the existing OPEs/OREs into forward secure OREs,with the goal of minimizing the extra burden incurred on computation and storage.We also present its security proof,and execute some experiments to analyze its performance.The proposed compilation is highly efficient and forward secure.
文摘A new type offinite volume WENO schemes for hyperbolic problems was devised in[33]by introducing the order-preserving(OP)criterion.In this continuing work,we extend the OP criterion to the WENO-Z-type schemes.Wefirstly rewrite the formulas of the Z-type weights in a uniform form from a mapping perspective inspired by extensive numerical observations.Accordingly,we build the concept of the locally order-preserving(LOP)mapping which is an extension of the order-preserving(OP)mapping and the resultant improved WENO-Z-type schemes are denoted as LOP-GMWENO-X.There are four major advantages of the LOP-GMWENO-X schemes superior to the existing WENO-Z-type schemes.Firstly,the new schemes can amend the serious drawback of the existing WENO-Z-type schemes that most of them suffer from either producing severe spurious oscillations or failing to obtain high resolutions in long calculations of hyperbolic problems with discontinuities.Secondly,they can maintain considerably high resolutions on solving problems with high-order critical points at long output times.Thirdly,they can obtain evidently higher resolution in the region with high-frequency but smooth waves.Finally,they can significantly decrease the post-shock oscillations for simulations of some 2D problems with strong shock waves.Extensive benchmark examples are conducted to illustrate these advantages.