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    WNUS property of Musielak-Orlicz sequence spaces
    WU Chun-xue
    J4   
    Abstract9038)      PDF(pc) (188KB)(1299)       Save
    The coefficient R(X) is calculated for Orlicz sequence spaces equipped with the Luxemburg norm and for Cesaro spaces cesp(1<p<∞).An example of nonreflexive Banach spaces X with R(X)<2 is given.It shows that property weak nearly uniformly smooth (WUNS) is essentially stronger than the inequality R(X)<2.
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    A study on the optimal ratio of stateowned stock in SOEs' reform under open conditions
    MENG Qing-chun and SUN Zhi-xia
    J4   
    Abstract8666)            Save
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    On a result of R.Bruck
    LI Xiao-lingsup> and HAN Qi
    J4   
    Abstract8428)      PDF(pc) (243KB)(1146)       Save
    The uniqueness problem of meromorphic functions which has few poles and shares a small meromorphic function with their linear differential polynominals is studied to improve the previous results of R.Bruck, Q.C.Zhang, A.Al-Khaladi, et al.
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    A schematic extension of IMTL-logic algebras#br#
    ZHOU Jian-ren1,2, WU Hong-bo2*
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    DOI: 10.6040/j.issn.1671-9352.0.2013.291
    Mean model based IBCF algorithm
    QI Li-li, SUN Jing-yu*, CHEN Jun-jie
    J4    2013, 48 (11): 105-110.  
    Abstract6206)      PDF(pc) (1451KB)(581)       Save

    The item-based collaborative filtering algorithm (IBCF),a recommendation algorithm with high precision,simple and easy to use in actual system, is widely used in the field of recommendation systems. But it meets a higher computational time complexity for similar calculation because of the long length of item vector. In this paper, a sampled approach firstly is suggested to represent an item vector called mean model item vector representation through analyzing theory of IBCF algorithm, to solve the problem of the long length of item vector and cut down the computational time. Experiments using Movie Lens datasets show that the algorithm is very efficient to cut down the computational time on the premise of accuracy. Furthermore, some right sampling methods can be used to optimize the calculation method of similarity in order to meet practical application requirement.

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    Effects of SDS on the pore structure of ZnO bulk porous nanosolids
    LI Mei,SUN Hai-yan,LIU Xiu-lin,XU Hong-yan,CUI De-liang* and JIANG Min-hua
    J4   
    Abstract4564)      PDF(pc) (245KB)(1127)       Save
    ZnO bulk porous nanosolids were successfully prepared by a novel liquid solvothermal hot press method using ZnO nanoparticles and sodium dodecyl sulphate (SDS) solution as the starting materials. The results show that the pore structure parameters of ZnO bulk porous nanosolids could be adjusted by changing the concentration of the SDS solution. At the beginning, the uniformity of the pore diameter improved with an increase of the concentration of the SDS solution and it reached its maximum at a concentration of 4.34×10-1mol/L. If the concentration is increased further, the uniformity of the pore diameter is again decreased. In addition, the FTIR spectra of ZnO bulk porous nanosolids indicate that a few SDS molecules remaine in the pores of the ZnO bulk porous nanosolids.
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    Security proofs of the 2m-root identification scheme under concurrent attacks
    YAN Shao-xiang
    J4   
    Abstract4245)      PDF(pc) (227KB)(1418)       Save
    It is proved that it is secure under the concurrent attacks if factoring integers is hard.
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    The Shark-Search algorithm based on clustering links
    SU Qi,XIANG Kun and SUN Bin
    J4   
    Abstract4041)            Save
    Based on the analysis of the focused-crawling algorithm Shark-Search, an improved Shark-Search algorithm with link clustering is proposed. The new algorithm by several comparable experiments is validated. The results show that it could identify the relevance between link and focused topic more effectively.
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    On Nega-Hadamard transform and negabent functions
    ZHUO Ze-peng, CHONG Jin-feng, WEI Shi-min
    J4    2013, 48 (7): 29-32.  
    Abstract3323)      PDF(pc) (937KB)(393)       Save

    Some of the properties of Nega-Hadamard transform are studied, such as, the relationship between the Nega-Hadamard transform and the nega-crosscorrelation is given. Also, the special Boolean function by concatenation is presented, and its nega-Hadamard transform is investigated. Based on it, the negabent functions in n+2 variables from two negabent functions in n variables is presented.

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    Weyl's theorem for 2×2 upper triangular operator matrices
    LI Yuan
    J4   
    Abstract2949)      PDF(pc) (214KB)(1123)       Save
    The conditions under which Weyl's theorem and Browder's theorem survive for 2×2 upper triangular operator matrices in Hilbert space are considered and explored.
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    Additivity of the gexpectation for affinerelated random variables
    QIN Dong
    J4   
    Abstract2516)      PDF(pc) (208KB)(1079)       Save
    When g satisfies g(y,0,t)=0,(y,t)∈R×[0,T], the g-expectation is additive for all affinerelated random variables if and only if g=μt|zt|+vtzt. If g need not satisfy g(y,0,t)R×[0,T], the g-expectation is additivity for all affinerelated random variables if and only if g=μt|zt|+vtzt+vt′yt, where μt, vt, vt′ are continuous functions on [0,T].
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    Function Srough sets and its F-heredity law
    SHI Kaiquan
    J4   
    Abstract2158)            Save
    Based on function S-rough sets, the concepts of F-generation, F-heredity, and the characteristics of F-heredity of system rough law are given, and the principle of F-heredity characteristic and attributes characteristic principle of F-heredity of system rough law are presented. F-heredity relies on the attributes complement to the attributes set α. From such discussion, the law mining by the method of F-heredity is presented
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    J4   
    Abstract2085)            Save
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    Interval decomposition of function S-rough sets
    PEI Hai-feng and XU Xiao-jing
    J4   
    Abstract1937)            Save
    Interval equivalence classes and interval function S-rough sets are defined based on interval attribute of function S-rough sets, and the finite covering theorem of closed interval equivalence classes and that of closed interval function S-rough sets are put forward. The relation of function S-rough sets and S-rough sets is also theoretically proved.
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    New word identification based on largescale corpus
    SHI Shui-cai,YU Hong-kui,LV Xue-qiang,LI Yu-qin
    J4   
    Abstract1918)            Save
    String frequent static, sub string reduction and several filtering method are used to analyze one set Chinese new word mining system and identify new word by using character, word and N-gram dictionary based on statistic largescale corpus.With the system based on those methods, new word without length and domain limit can be identified.
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    Rough graph and its structure
    HE Tong,LU Chang-jing,SHI KAi-quan,
    J4   
    Abstract1838)            Save
    Abstract: By combining the rough set theory with the traditional graph theory, the equal definition of classical graph is presented based on the idea of rough set theory. In general, the definition of rough graph is given. Furthermore, the matrix expression of rough graph and the rough characteristic analysis of rough graph are also given. Rough graph extends the results of classical graph theory. It is the graph that can be used to research uncertainty problems, and is also a new research tool to analyze the system rough characteristic.
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    Fixed point theorems for the generalized contractive mappings and mapping pairs in cone metric spaces
    YUAN Qing,GAO Jian-jun,WANG Yan-wei
    J4    2008, 43 (5): 82-86 .  
    Abstract1830)      PDF(pc) (200KB)(714)       Save

    Since the notation of cone metric spaces was raised, several authors have studied its constructions and properties. The results on the existence of fixed points of generalized contractive mappings were extended by relaxing the contractive conditions. The existence of common fixed points of generalized contractive mapping pairs was also discussed. The obtained results extend the recent relative results and the classical theorems in metric spaces.

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    A kind of finite volume method for pricing American options
    SUN Peng,ZHANG Lei and ZHAO Wei-dong
    J4   
    Abstract1818)      PDF(pc) (272KB)(1490)       Save
    The numerical solution for pricing American options under stochastic volatility is considered. A new type of 9points finite volume scheme and related operator splitting scheme are proposed. This scheme is proved to satisfy the maximum principle and the error estimates are derived. Numerical results are presented to show the validity of this scheme.
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    LQ nonzero sum stochastic differential game under partial observable information
    WANG Guang-chen
    J4   
    Abstract1803)      PDF(pc) (211KB)(1506)       Save
    Combining forward and backward stochastic differential equations and filtering techniques, the Nash equillibrium point of a type of partially observed LQ ninzero sum stochastic different game problem is obtained.
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    The quadratic Waring-Goldbach problem
    LIU Jian-ya and ZHAN Tao
    J4   
    Abstract1781)      PDF(pc) (442KB)(1658)       Save
    The purpose of this paper is to briefly survey the recent progress towards the quadratic Waring-Goldbach problem. Contents of the paper are as follows: the Waring-Goldbach problem, the circle method, Hua's theorem with five almost equal prime variables, treatment of the enlarged major arcs, the major arcs in the representation by four squares of primes, mean-value estimates for Dirichlet polynomials, the minor arcs and exceptional set in the representation by four squares of primes, estimates of exponential sums over primes, sieve methods in the representation by four squares of primes, Lagrange's theorem with almost prime variables, the Linnik-Gallagher problem, new results for Hua's theorem with five almost equal prime variables, sums of three squares of almost primes, Sarnak's conjecture and ternary quadratic forms.
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    The characteristic of S-rough sets on CS(K)
    ZHANG Chun-ying,XUE Ding-jun,and LIU Bao-xiang
    J4   
    Abstract1767)            Save
    According to the equivalence class, the concept nodes of CS(K) (Concept Lattice) are partitioned. The characteristics of rough sets and S-rough sets are analyzed. The definitions of rough sets and S-rough sets on CS(K) are given and the related theorem is presented. The relation between the concept lattice and S-rough sets is found. At last, the characteristics of S-rough sets are illnstrated with an example.
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    Robust option pricing model and empirical performance
    and PENG Shi-ge
    J4   
    Abstract1744)            Save
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    Research advances of novel nonlinear optical crystals based on second-order Jahn-Teller effects (SOJT)
    ZHANG Jun-jie, ZHANG Zhong-han, TAO Xu-tang*
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2011, 46 (10): 99-120.  
    Abstract1738)      PDF(pc) (5876KB)(1567)       Save

    Explorations of new inorganic second-order nonlinear optical (NLO) materials is one of the current frontier topics due to their optoelectronics application such as frequency shifting, optical modulating, telecommunications and signal processing. Since 1998, a series of noncentrosymmetric (NCS) and polar oxides containing cations susceptible to second-order Jahn-Teller (SOJT) distortions, specifically, octahedrally coordinated d0 transition metals (TMs: Mo6+,W6+,V5+,Nb5+,etc.) and cations with stereochemically active lone pairs (SCALP, e.g. I5+, Te4+, Se4+, Sn2+, etc.), were successfully synthesized. Many of these materials exhibit large powder second-harmonic generation (SHG) efficiencies (> 400×α-SiO2). This paper reviews the progress on the materials in the past decade, including the search for new materials and crystal growth. The materials are divided into three categories: NCS oxides containing one kind of SOJT cations (d0 or SCALP), NCS oxides containing both kinds of SOJT cations, and NCS oxides containing SOJT cations and other NCS building units such as borate πorbital systems, tetrahedral groups and d10 transition metal cations (Zn2+, Cd2+, Sn4+, etc.).

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    Topics in L-functions
    HU Pei-chu, WU Ai-di
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2016, 51 (6): 1-15.   DOI: 10.6040/j.issn.1671-9352.0.2016.185
    Abstract1725)      PDF(pc) (851KB)(604)       Save
    In this survey, we introduce some propositions of L-functions in the extended Selberg class.
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    Ionic liquid gels
    Juan GAO,Xiao-lin WANG,Heinz HOFFMANN,Jing-cheng HAO
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2019, 54 (1): 1-18.   DOI: 10.6040/j.issn.1671-9352.9.2018
    Abstract1714)   HTML69)    PDF(pc) (20377KB)(424)       Save

    Ionic liquid gels (Ionogels) are the kind of gels formed by using ionic liquids as dispersing media. As new mixed materials, ionogels not only keep the original properties of ionic liquids, but also solve the problems of ionic liquid spillover. The high plasticity in shape meets the needs of special materials and expands the application of ionic liquids. There are many kinds of ionogels, which can be divided into physical and chemical types. Recent years, the structures, properties and applications of ionogels have become one of the hot topics in colloid and interface sciences, as well as the main contents of soft matters. The progress in the construction, structures, properties and applications of ionogels in recent years is reviewed and summarized, which can provide an important theoretical guidance for the construction and applications of ionogels in the future.

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    Nonparametric estimation and simulation of backward stochastic differential equation
    YANG Wei-qiang and YANG Li
    J4   
    Abstract1710)            Save
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    Extended probabilistic data model based on XML
    ZHANG Qun,WANG Xin-jun,WU Xin
    J4   
    Abstract1703)      PDF(pc) (714KB)(1056)       Save
    The research on the probabilistic data model has received extensive attentions except for the management of probabilistic data from various data sources. An extended XML probabilistic data model was proposed based on an existent model. This new model is no longer confined to evaluate query operation in the internal model. Instead, it makes full use of the data sources' own credit degrees, size and other information to support query and merging operations between different XML documents. Moreover, the data dependent problem caused by importing probability in XML was also resolved in the new model.
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    Naive Bayes Chinese text classification based on core words of class
    YUAN Fang,YUAN Jun-ying
    J4   
    Abstract1701)            Save
    Abstract:From the view of manual classification, words in title,abstract and key words are more important than others. A classification mode is advanced based on core words of class. This classification mode extracts core words from title, abstract and key words, and these core words' effect is strengthened via the mode of weight. The experiment of Naive Bayes classification indicates that this method can effectively improve classification precision of Chinese texts.
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    Some results on fractional kuniform graphs
    CAI Jian-sheng,YU Ji-guo ,and WANG Ji-hui,
    J4   
    Abstract1701)            Save
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    On ColAutS(G)-vertex-transitive Cayley graphs of semigroups
    ZENG Yan-shan,FAN Suo-hai
    J4   
    Abstract1693)            Save
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    Experiment on coherent motions in the turbulent nearwall region over a dragreducing grooved surface
    LI Xin-hua,DONG Shou-ping,ZHAO Zhi-yong and CHEN Jun-feng,
    J4   
    Abstract1680)            Save
    Measurements of flow field by means of a twocomponent LDV system have been carried out in turbulent boundary layers over a smooth surface and a drag reducing grooved surface with a zero pressure gradient. Variations of the second and thirdorder moments of velocity fluctuations are investigated to give thorough information on coherent motions in the turbulent nearwall region over both surfaces.
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    Synthesis and characterization of 5-bromo-3-sec-butyl-6-methyluracil
    REN Hui-xue,YANG Yan-zhao,LIN Ji-mao,QI Yin-shan,ZHANG Ye-qing
    J4   
    Abstract1648)      PDF(pc) (187KB)(901)       Save
    A new synthetic method of 5-bromo-3-sec-butyl-6-methyluracil(Bromacil) was described. Bromacil was synthesized using 2-bromobutane and urea as the starting materials in three steps including condensation, cyclization and bromination with total yield of 61%. The structure of Bromacil was characterized by
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    Improved collision attack on 7 round AES-192
    ZHANG Wen-yu and ZHANG Hai-na
    J4   
    Abstract1639)      PDF(pc) (199KB)(1458)       Save
    An improved collision attack on 7 round AES-192 is given. This attack is based on the result of Gilbert and Minier and the utilization of some properties of AES-192 key schedule. The improved attack can recover the main key by about 2120 encryption operations and 2123 bytes of memory. Compared with Gilbert-Minier's attack, the time complexity of this attack decreases 224 times with 28 times memory increasing. When the same memory is used as Gilbert-Minier's attack, the time complexity is about 2127 encryption operations.
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    Statistical models of synchronous and asynchronous communication
    CHEN Lei
    J4   
    Abstract1615)            Save
    The precise definitions of synchronous and asynchronous communication modes are described in this paper. Statistical models for these two forms of communication are proposed. The concept of Communication Entropy (Comtropy) is defined. This will lay the foundation for the further research of networkmediated communication.
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    Properties of maximal mathematical expectation
    SHI Heng-lu,DENG Wei and QI Lu
    J4   
    Abstract1612)      PDF(pc) (190KB)(1303)       Save
    Maximal mathematical expectation is nonlinear as well as g-expectation. There are some connections between these two nonlinear expectations. Some special useful properties are obtained by the definition of maximal mathematical expectation or via g-expectation.
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    Sums of nine almost equal prime cubes
    XU Yun-fei and Lǔ
    J4   
    Abstract1609)            Save
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    Invertible incline matrices and ranks of incline matrices
    ZHANG Li-mei,QIAO Li-shan,LI Ying
    J4   
    Abstract1606)      PDF(pc) (227KB)(1037)       Save
    Inclines are additively idempotent semi-rings in which the products are less than or equal to either factor. Some properties of the invertible incline matrices are discussed, and the ranks of the invertible incline matrices are proved to be full. The row ranks, the column ranks and the Schein ranks of incline matrices are studied and important properties of the Schein ranks of incline matrices are given.
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    Automatic text classification model based on random forest
    ZHANG Wei-hua,WANG Ming-wen,GAN Li-xin
    J4   
    Abstract1602)            Save
    Abstract: With the rapid development of World Wide Web, text classification has become the key technology in organizing and processing large amount of document data. Random forests are a combination of tree predictors such that each tree depends on the values of random vector sampled independently and with the same distribution for all trees in the forest. The generalization error for forests converges to a limit as the number of trees in the forest becomes large. In experiments it is compared to C4.5, KNN, SMO and SVM, and the results show that its performance is higher than C4.5 and comparable with KNN, SMO and SVM. It is a promising technique for text categorization.
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    Provable degree of formula on theories in the propositional fuzzy logic system God
    GAO Qin,ZHANG Xing-fang,WANG Qing-ping
    J4   
    Abstract1601)      PDF(pc) (240KB)(1115)       Save
    Based on the concept of provable degree of formula on theories in propositional fuzzy logic systems, the calculating formula provable degree of formula on theories was given in the propositional fuzzy logic system, and its properties were shown.
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    Robust H∞ filtering for a class of nonlinear stochastic uncertain systems
    HUANG Yu-lin,ZHANG Wei-hai and LI Qing-hua
    J4   
    Abstract1590)            Save
    For a class of nonlinear stochastic uncertain systems, its robust H∞ filtering problem has been studied. It is assumed that the uncertain matrices in the nonlinear term are timevarying and norm bounded, while the nonlinear terms satisfy uniformly Lipschitz condition at the origin, and furthermore, the external disturbance is a stochastic process. A sufficient condition for the existence of H∞ filtering of the nonlinear stochastic systems is given via linear matrix inequalities, and an example is also presented to illustrate the effectiveness of the result.
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