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    Local optimal granularity selections in generalized multi-scale decision systems
    GU Shen-ming, LU Jin-lu, WU Wei-zhi, ZHUANG Yu-bin
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (8): 1-8.   DOI: 10.6040/j.issn.1671-9352.4.2018.184
    Abstract1312)      PDF(pc) (489KB)(849)       Save
    People tend to choose the appropriate level of granularity to solve problems in application. In the classical multi-scale decision systems, during the process of constructing the levels of granularity, some fixed levels of granularity are selected manually for attribute values. Aiming at generalized multi-scale decision systems in this paper, the levels of granularity are constructed by using the scale combination of attribute values. Furthermore, the selection problems of local optimal granularity are studied. The concept of generalized multi-scale decision systems is introduced firstly. Then, notions of the optimal granularity and the local optimal granularity in consistent generalized multi-scale decision system are defined, and the algorithms for finding optimal granularities and the local optimal granularities are described. Finally, the generalized decisions are introduced to inconsistent generalized multi-granular decision systems, the generalized optimal granularity and the generalized local optimal granularity are defined, and the algorithms for finding the generalized optimal granularity and the generalized local optimal granularity are also investigated.
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    Anomaly detection model of host group based on graph-evolution events
    YE Xiao-ming, CHEN Xing-shu, YANG Li, WANG Wen-xian, ZHU Yi, SHAO Guo-lin, LIANG Gang
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (9): 1-11.   DOI: 10.6040/j.issn.1671-9352.2.2017.169
    Abstract1311)      PDF(pc) (5937KB)(592)       Save
    Aiming at the communication behavior based on service aggregation and the new collaborative attack mode that is typical of distributed attack in the network environment, the anomaly detection model of host group based on graph-evolution events is proposed. It analyzes the potential socialization of actors, the clustering of host clusters and the dynamics of their group behavior. The model has the characteristics of no parameters and extensible data magnitude. The dynamic evolution events and detection algorithms are defined and proposed to detect abnormal host groups. The model is implemented and deployed on Spark, and the data from the actual computer and network environment is analyzed and verified. The experimental results show that this model can effectively describe group behavior, expose important graph-evolution events, and locate the host group with abnormal occurrence accurately. The detection rate of group members is 95.09%.
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    Privacy preservation for location-based services
    Hai-yan KANG,Wan-xiang ZHU
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (11): 35-50.   DOI: 10.6040/j.issn.1671-9352.0.2018.128
    Abstract955)   HTML27)    PDF(pc) (1792KB)(559)       Save

    The disclosure of privacy involves not only the users' locations and queries data, but also the users' identities, interests, social habits, behavior patterns and privacy hidden in these data. A review of privacy preserving for location-based services (LBS) is provided. The application scenarios of location services is introduced, the method of location privacy attack is given. The existing research on the privacy protection system structure and protection technology is summarized. Finally, future research is prospected, and a cache-based spatiotemporal disturbance method and LBS privacy protection metric hypothesis scheme are proposed.

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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
    Abstract1749)   HTML70)    PDF(pc) (20377KB)(429)       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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    Composition and structure on attribute reduction of interval-set concept lattices
    ZHANG En-sheng
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (8): 17-24.   DOI: 10.6040/j.issn.1671-9352.4.2018.052
    Abstract1574)      PDF(pc) (491KB)(408)       Save
    Interval-set provides a research tool for processing partially known concepts and for approximating undefinable or complex concepts. Concept lattices is a powerful tool for data analysis in machine learning, data mining, knowledge discovery, information retrieval, and so on. Interval-set concept lattices is the product of the combination concept lattices and the interval-set theory,which is a powerful tool for data analysis in machine learning, data mining, knowledge discovery and information retrieval on the information systems of partially known concepts or undefinable concepts. The attribute reduction of interval-set concept lattices is a kind of the method which reveals the elementary character of interval-set concept lattices attribute. This paper reveals the composition and structure of the attribute reduction of interval-set concept lattices. The equivalence relative necessary attributes are not in the same attribute reduction; and the intersection of attribute reduction and any relative necessary attribute equivalence class is nonempty. The set of the core attributes and the relative necessary attributes chosen by taking an attribute from each relative necessary attribute equivalence class must be an attribute reduction.
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    Academic paper recommendation based on heterogeneous network embedding
    Kan XU,Rui-xin LIU,Hong-fei LIN,Hai-feng LIU,Jiao-jiao FENG,Jia-ping LI,Yuan LIN,Bo XU
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2020, 55 (11): 35-45.   DOI: 10.6040/j.issn.1671-9352.1.2019.017
    Abstract141)   HTML13)    PDF(pc) (4302KB)(383)       Save

    This paper focuses on the extraction and utilization of information from heterogeneous information network recommendation, and proposes a heterogeneous network embedding-based academic paper recommendation method. The proposed method uses the random walk strategy guided by the meta-path to generate the sequence of nodes. Then, for each meta-path, the unique embedding representation of nodes is learned by maximizing its co-occurrence probability with the adjacent nodes in the sequence obtained from the given meta-path. In addition, in order to fuse the low-dimensional representation of nodes in differentmetapaths into the final output of heterogeneous information network embedding, the different fusion functions are designed to achieve this goal, and attention mechanism is introduced to recommendation system. This paper applies the heterogeneous information network based on meta paths to solve the problem that most recommendation methods based on heterogeneous information networks rely on path similarity, which can not fully mine the potential structural characteristics of users and projects. We use DBLP data set to validate the effectiveness of the proposed model, which achieved better performance compared with the traditional model on RMSE.

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    Hopf bifurcation and spatial patterns in a delayed diffusive predator-prey system with Holling-III functional response and linear harvesting effect
    ZHANG Dao-xiang, SUN Guang-xun, MA Yuan, CHEN Jin-qiong, ZHOU Wen
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (4): 85-94.   DOI: 10.6040/j.issn.1671-9352.0.2017.509
    Abstract677)      PDF(pc) (7198KB)(376)       Save
    The spatial dynamics in a delayed diffusive predator-prey system with Holling-III functional response and linear harvesting effect is studied. Firstly, the local stability of positive equilibrium of the system and the condition of Hopf bifurcation are obtained by using the stability theory and the bifurcation theory. Secondly, the direction of Hopf bifurcation and the stability of the bifurcating periodic solutions are determined by the normal form theory and the center manifold theorem.Furthermore, the instability of Hopf bifurcation leads to the formation of spatial pattern of system. Finally, the correctness of the theoretical results is verified by numerical simulations, which shows that the system has rich dynamic behavior.
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    Itô-Henstock integration of the fuzzy stochastic process
    GONG Zeng-tai, SU Ai
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2019, 54 (8): 1-13.   DOI: 10.6040/j.issn.1671-9352.0.2019.235
    Abstract403)      PDF(pc) (900KB)(369)       Save
    The fuzzy Itô-Henstock integral and the fuzzy Itô-McShane integrals for adapted fuzzy stochastic process with respect to a Brownian motion are defined and their properties are discussed. In addition, the characterization theorems are given and their interrelation of between the fuzzy Itô-Henstock integral and the fuzzy Itô-McShane integral is investigated. The result shows that the fuzzy Itô-Henstock integral is equivalent to the fuzzy Itô-McShane integral when its primitive of fuzzy Itô-Henstock integral is Itô absolutely continuous.
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    Application impacts analysis on natural forestry management for pine plantation in central and southern mountainous area of Shandong province
    Chun-hui LING,Ming-zhong ZHANG,Gui-yun LYU,Hao-ran CUI,Pan YAP,Ye WEI,Sheng-yuan LIU,Feng-yun MA,Hua-tian WANG,Xiu-mei LIU,Ling MA
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2020, 55 (11): 8-17.   DOI: 10.6040/j.issn.1671-9352.0.2020.199
    Abstract74)   HTML12)    PDF(pc) (2192KB)(358)       Save

    The near-natural management experiments were carried out at three forestry stations of Culaishan, Taishan and Mingguangsi, with long-time thinning possesses of 2, 10 and 3 years, respectively. The results revealed that: (1) The effects of thinning management could promote the seedling growth compared to the controlled treatment (CK), the main height, diameter at breast height (DBH) and canopy diameter increased by 3.13%-12.89%, 3.03%-8.91% and 2.75%-25.91%, respectively. Similarly, the annual mean diameter of residual trees height, DBH and diameter of canopy also improved by 21.43%-66.67%, 9.21%-26.15% and 64.29%-300% when suffered to near-natural processing. (2) The intermediate cutting changed the canopy gap, led to a decrease in crown closure. On the contrary, it caused an increase in plant species of shrub layer especially for the light-loving plants like Platycladus orientalis and Ailanthus altissima. Consistently, it could contribute to the herbs diversity, which caused improvements of diversity indexes like Simpson, Shannon-wiener and Gleason in pure pine stand and mixed pine-oak forest compared with that in CK. At the same time, the important values of Digitaria sanguinalis, Spodiopogon sibiricus and Carex rigescens elevated. (3) The tending measurement resulted in an improvement of soil pH, and a decrease of bulk density. As well, it had a potential to accelerate the nutrient metabolism for the increasing enzyme activities of catalase, phosphatase, sucrase and urease, which increased by 6.74%-29.33%, 4.79%-4.99%, 2.13%-10.34% and 1.25%-25.56%, respectively. It could be seen that the tending operation could benefit to the stand growth, enrich the undergrowth diversity, also improve the soil quality in different stand conditions.

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    BERT-IDCNN-CRF for named entity recognition in Chinese
    Ni LI,Huan-mei GUAN,Piao YANG,Wen-yong DONG
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2020, 55 (1): 102-109.   DOI: 10.6040/j.issn.1671-9352.2.2019.076
    Abstract1519)   HTML42)    PDF(pc) (2001KB)(356)       Save

    The pre-trained language model, BERT (bidirectional encoder representations from transformers), has shown promising result in NER (named entity recognition) due to its ability to represent rich syntactic, grammatical information in sentences and the polysemy of words. However, most existing BERT fine-tuning based models need to update lots of model parameters, facing with expensive time cost at both training and testing phases. To handle this problem, this work presents a novel BERT based language model for Chinese NER, named BERT-IDCNN-CRF (BERT-iterated dilated convolutional neural network-conditional random field). The proposed model utilizes traditional BERT model to obtain the context representation of the word as the input of IDCNN-CRF. At training phase, the model parameters of BERT in the proposed model remain unchanged so that the proposed model can reduce parameters training while maintaining polysemy of words. Experimental results show that the proposed model obtains significant training time with acceptable test error.

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    Semilattice-ordered completely regular periodic semigroups
    SHAO Yong
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (10): 1-5.   DOI: 10.6040/j.issn.1671-9352.0.2017.506
    Abstract1015)      PDF(pc) (315KB)(352)       Save
    It is proved that the multiplicative reducts of semilattice-ordered completely regular periodic semigroups are regular orthocryptogroups through the research of semilattice-ordered completely regular periodic semigroups. Semilattice-ordered completely regular periodic semigroups are equivalent characterizations of semilattice-ordered regular band and distributive lattices are obtained by using partial orders.
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    Vertex distinguishing edge coloring of a hexagonal system
    ZHANG You, HUANG Li-na, LI Mu-chun
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (12): 41-47.   DOI: 10.6040/j.issn.1671-9352.0.2017.139
    Abstract365)      PDF(pc) (584KB)(351)       Save
    Let H(m,n) be a hexagonal system for the length of n and the width of m adjacent hexagons which the shape likes a parallelogram. The vertex distinguishing edge chromatic number of H(1,n) satisfies vertex distinguishing edge coloring conjecture by designing the coloring algorithm. An upper bound of the vertex distinguishable edge chromatic numbers of H(m,n) for m≥2 is given.
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    Dynamic discovery of authors research interest based on the combined topic evolutional model
    YU Chuan-ming, ZUO Yu-heng, GUO Ya-jing, AN Lu
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (9): 23-34.   DOI: 10.6040/j.issn.1671-9352.1.2017.044
    Abstract1455)      PDF(pc) (4162KB)(349)       Save
    We propose a new combined topic model, i.e. author topic time-latent dirichlet allocation(ATT-LDA)with author ranking(AR), for the of dynamic discovery of researchers' interest, which is based on the academic literature in the financial field. Through the proposed model, we can easily acquire the probability distribution of the authors' interest, as well as the probability distribution of topics on deferent words. The influence of the ranking in the co-author list are fully taken into consideration. The empirical study shows that the proposed method can effectively reveal the dynamic change of interest of the authors in the financial field.
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    Existence of periodic solutions of a class of third order delay differential equations in Banach spaces
    CHEN Yu-jia, YANG He
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (8): 84-94.   DOI: 10.6040/j.issn.1671-9352.0.2017.582
    Abstract1094)      PDF(pc) (510KB)(335)       Save
    Applying the monotone iterative method of upper and lower solutions, we discuss the existence of 2π-periodic solutions for the third-order differential equation with delays in ordered Banach space Eu(t)+M0u(t-τ0)=f(t,u(t), u(t-τ1), u(t-τ2)), t∈R,where f:R×E3→E is a continuous function which is 2π-periodic in t, and τ012 are positive constants. By establishing a new maximum principle, a monotone iterative procedure for the equation is constructed. Some existence and uniqueness results of 2π-periodic solutions for this equation are obtained.
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    Research on supply chain decision making of equitable retailers with fair sensitivities
    ZHANG Ke-yong, LI Jiang-xin, YAO Jian-ming, LI Chun-xia
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (9): 83-94.   DOI: 10.6040/j.issn.1671-9352.0.2018.032
    Abstract1357)      PDF(pc) (1177KB)(326)       Save
    In order to study the influence of heterogeneity of subject of fair preference on the decision of supply chain, fair sensitivity was introduced to the decision model of fair preference decision-maker. We build a secondary supply chain consisting of a manufacturer, two competing retailers, one of which has a fair preference and fair sensitivity. Based on the social comparison theory, a supply chain decision model with horizontal equity preference and vertical equity preference was established, and the influence of fair sensitivity coefficient on decision variables and utility of decision makers was obtained. Finally, numerical examples were used to verify the conclusion. The results show that the existence of fair preference and fair sensitivity does not increase the utility value of retailer itself, and it increases the competition between the two retailers under the horizontal equity preference. In the adverse unfair situation, the utility of the retailer increases with the increase of the fair sensitivity coefficient, and decreases with the increase of the fair sensitivity coefficient in the favorable unfair situation. Therefore, in the case of unfair adverse circumstances, the retailer should remain humble inferiority, and should not overestimate his own abilities and status. But in the case of favorable unfair circumstances, the retailer should be confident. Only in this way can he keep the utility maximization.
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    Comparative study on genetic structure of three color variants of the sea cucumber (Apostichopus japonicus) based on mitochondrial and ribosomal genes
    Zhan-sheng GUO,Zhen WANG,Xu-guang HOU,Hai-tao ZHANG
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2020, 55 (11): 1-7.   DOI: 10.6040/j.issn.1671-9352.0.2020.231
    Abstract85)   HTML15)    PDF(pc) (869KB)(323)       Save

    The sea cucumber Apostichopus japonicus is an important marine aquatic species in China. Selecting good breeding is a major issue for sea cucumber aquaculture, and body color is chosen as an important consideration. In order to explore the genetic structure and phylogenetic relationship of sea cucumber populations with different body color characteristics, 16S rRNA, COⅠ and 18S rRNA-ITS-28S rRNA sequences were amplified and sequenced. The results showed that the lengths of 16S rRNA, COⅠ and 18S rRNA-ITS-28S rRNA sequences were 812-830 bp, 877-915 bp and 1 536-1 572 bp, respectively. In the green, white and purple morphs of the sea cucumber, 4/5/5, 5/3/4, and 4/4/3 haplotypes were detected in 16S rRNA, COⅠ and 18S rRNA-ITS-28S rRNA sequences, respectively. The number of polymorphic loci in the COⅠ sequences was the highest, and that of 16S rRNA sequences was the smallest. The genetic distances of 16S rRNA, COⅠ and 18S rRNA-ITS-28S rRNA sequences among three color morphs were both small, ranging from 0-0.014 7, 0-0.021 2, and 0-0.010 3, respectively, and they did not reach the species differentiation level. The phylogenetic tree was constructed based on the COⅠ sequences, and Strongylocentrotus purpuratus was chose as the outgroup. The results showed that the white sea cucumbers were clustered into one branch, the purple and green sea cucumbers were cross-aggregated with each other and could not be distinguished.

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    Calibrating option pricing models with cross entropy bat algorithm
    LI Guo-cheng, WANG Ji-xia
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (12): 80-89.   DOI: 10.6040/j.issn.1671-9352.0.2018.057
    Abstract338)      PDF(pc) (1588KB)(318)       Save
    Parameter estimation of option pricing model is usually a nonlinear optimization problem with no convex, which leads to the classical optimization method cannot be applied. Based on cross entropy bat algorithm, we studied how to solve parameter estimation problems of option pricing models such as Mertons jump-diffusion model, Hestons stochastic volatility model and Batess stochastic volatility with jump model. The empirical results show that the cross entropy bat algorithm is feasible and effective for solving the parameter estimation problems of option pricing model.
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    Fault tracing method of industrial production control data network based on SDG simplified model
    Yan-hua YANG,Li-gang YAO
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2020, 55 (11): 46-57.   DOI: 10.6040/j.issn.1671-9352.0.2020.353
    Abstract85)   HTML9)    PDF(pc) (1763KB)(314)       Save

    For the fault diagnosis and source tracing in industrial production control data network, this paper proposes a solution based on SDG simplified model. Firstly, a SDG model is established based on the structural characteristics of the industrial production control data network, then the search space for fault location is reduced through hierarchical and demarcated modeling method.On this basis, according to the observed signal amount extracted when the business alarm occurs, analyse the survival of the nodes based on the longitudinal data and survival data. Secondly, combined with the analysis of the characteristics of network faults, the single-node fault detemination method is used to determine whether each node device is faulty. Finally, based on the fault cause classification of the fault tracing database in the traceability diagnosis rules, the root cause of the network fault is determined. Through the test and verification method, the feasibility of the proposed method in the industrial production control data network is verified, which can meet the requirements of rapid fault tracing.

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    Characterization of monoids by C(P')acts
    LIANG Xing-liang, WU Su-peng, REN Jun
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (10): 9-13.   DOI: 10.6040/j.issn.1671-9352.0.2017.512
    Abstract933)      PDF(pc) (343KB)(306)       Save
    Let S be a monoid. By using ring theory and module theory, C(P')right S-acts in the category of S-acts are introduced, and some important monoids, such as P(P')monoids, periodic monoids and so on, are characterized by C(P')property of S-acts. Further, some important results on C(P)right S-acts are extended. Meanwhile, an important significance to the application of regularity in S-acts is presented.
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    Effects of Piriformospora indica on growth and root morphology of Pinus thunbergii seedlings
    ZHOU Xiao-ying, LIANG Yu, DONG Zhi, LI Hong-li, ZHANG Meng-xuan, HAN Xiu-feng, FAN Xiao-li, FANG Yong
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (7): 7-14.   DOI: 10.6040/j.issn.1671-9352.0.2018.019
    Abstract333)      PDF(pc) (2218KB)(303)       Save
    In order to study the dynamic effects of Piriformospora indica on the growth and root morphology of Pinus thunbergii seedlings, we studied the effects of Piriformospora indica on the growth and root architecture, and root fractal dimension of Pinus thunbergii seedlings. The results showed that the promoting effect of Piriformospora indica on the growth of underground roots was earlier than that on aboveground parts, and the effect was significantly higher than aboveground parts. 15 to 30 days after Piriformospora indica was inoculated, the inoculation seem to have little effect on aboveground parts, but the promotion effect on root was obvious, while the aerial part had significant growth effect on the 60th day. Inoculation of Piriformospora indica can increase the above-ground and root biomass, and also significantly improve root length, branch number, surface area, volume and other configuration parameters and root fractal dimension, and promote the growth of Pinus thunbergii.
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    Forward-backward stochastic differential equations on Markov chains
    XIAO Xin-ling
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (4): 46-54.   DOI: 10.6040/j.issn.1671-9352.0.2017.483
    Abstract577)      PDF(pc) (421KB)(298)       Save
    In this paper, we mainly study the solutions about fully coupled forward-backward stochastic differential equations(FBSDE)on Markov chains. Using the usual method of continuation which is used to study fully coupled forward-backward stochastic differential equations, the Ito product rule of semimartingales, the Lebesgue control convergence theorem and iterative method, theorems about the solutions of the fully coupled forward-backward stochastic differential equations on Markov chains are obtained.
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    Differential privacy partitioning algorithm based on adaptive density grids
    YAN Yan, HAO Xiao-hong
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (9): 12-22.   DOI: 10.6040/j.issn.1671-9352.0.2017.418
    Abstract1327)      PDF(pc) (1990KB)(295)       Save
    In order to balance the influence of noise error and uniform hypothesis error for the two-dimensional partitioning publishing, a new hierarchical differential privacy partitioning algorithm DP-ADG is proposed. Firstly, the position space is clustered to form the density adaptive grids in the first layer. Then in the second layer, different partitioning methods are adopted for different density blocks. The noise error introduced by a large number of null nodes is avoided while reducing the uniform hypothesis error. While using the hierarchical partitioning strategy, different Laplace noise of different privacy budgets is added to the results of two phases according to the sequential composition of differential privacy, in order to realize the overall ε differential privacy protection for the publishing data. Experimental results show that the algorithm has good effect on improving the accuracy of range counting query, saving unnecessary spatial decomposition process, as well as improving the efficiency of the algorithm.
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    Complete noncompact Riemannian manifold with asymptotically nonnegative Ricci curvature
    CHEN Ai-yun, XUE Qiong, CHEN Huan-huan, XIAO Xiao-feng
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (4): 1-6.   DOI: 10.6040/j.issn.1671-9352.0.2017.480
    Abstract593)      PDF(pc) (353KB)(290)       Save
    We study the topology of complete noncompact Riemannian manifolds with asymptotically nonnegative Ricci curvature. By using extensions of Excess function and Busemann function, it is proved that they have finite topological type under sectional curvature bounded from nonnegative below kp(r)≥- C/((1+r)α) and large volume growth, which extend a series known results.
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    Some notes on E2-term of Adams spectral sequence
    LIU Yan-fang, WANG Yu-yu
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (8): 43-48.   DOI: 10.6040/j.issn.1671-9352.0.2017.383
    Abstract1204)      PDF(pc) (358KB)(285)       Save
    The E2-term of the Adams spectral sequence, which is the cohomology of mod p Steenrod algebra A, will be discussed by using the May spectral sequence. In the Adams spectral sequence, the non-triviality of (~overγ)s+3b1hn is given, and it doesnt be hitted by any element. These results are important for the detection of new family of elements in the stable homotopy groups of spheres.
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    Construction methods for a class of lightweight optimal S-boxes
    LI Ang, GUAN Jie
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (7): 85-94.   DOI: 10.6040/j.issn.1671-9352.0.2017.566
    Abstract638)      PDF(pc) (634KB)(278)       Save
    S-boxes are fundamental nonlinear components used in symmetric ciphers. The security of the ciphers is directly affected by the cryptographic properties of the S-boxes. This paper presents a construction method for a class of 4-bit optimal S-boxes, and proves that these optimal S-boxes can be classified into the same affine equivalent class G1. For each optimal S-boxes, we count their differential, linear properties and algebraic degree, then get the average number of equivalent gate of 25.6 in hardware implement. Furthermore, utilizing three-round MISTY and Feistel structure with sub-keys, we investigate the problem of constructing 8 bit S-boxes. Using a new definition called structure-optimality, we put forward a sufficient condition when 8-bit S-boxes reach the structure-optimality.
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    Attribute reduction of incomplete contexts based on similarity relations
    LI Tong-jun, HUANG Jia-wen, WU Wei-zhi
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (8): 9-16.   DOI: 10.6040/j.issn.1671-9352.4.2018.100
    Abstract1326)      PDF(pc) (450KB)(273)       Save
    The paper focuses on the attribute reduction of incomplete contexts. First, by comparing the values of the objects on each of the attributes, one kind of similarity relations is proposed in incomplete contexts, based on which decision rules with clear meaning can be revealed via rough approximation operators. Subsequently, one type of attribute reduction of incomplete contexts is defined, under which the similarity relations keep unchanged, some judgment theorems are given for attribute reduction, and different types of attributes for attribute reduction are characterized by the similarity relations. At last, by constructing a Boolean function with discernibility attributes among objects, an approach for attribute reduction is obtained, and an illustration example is taken to show the reliability of approach.
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    Expression, purification and crystallization of gas vesicle structure protein GvpC from the cyanobacterium Microcystis aeruginosa
    Bo-ying XU,Tian-tian ZHANG
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (11): 1-8.   DOI: 10.6040/j.issn.1671-9352.0.2018.200
    Abstract609)   HTML56)    PDF(pc) (14245KB)(273)       Save

    Preliminary crystallographic study on the gas vesicle structure protein GvpC from the cyanobacterium Microcystis aeruginosa was performed. Firstly, gene gvpC was cloned and expressed; then, the recombinant protein was purified by denaturation and renaturation and gel filtration chromatography; the result of renaturation was detected by circular dichroism. Crystal screening was performed by sitting drop vapor diffusion techniques. GvpC was overexpressed as inclusion body in E. coli, and then the protein has been purified through denaturation and renaturation. The result of circular dichroism indicated that GvpC was refolded successfully in vitro. Crystals of GvpC were also obtained by crystal screening. Hence, the three-dimensional structure of GvpC could be determinated by solving its crystal structure.

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    Release of the antifoulant in equilibrium swollen polymer: molecular dynamics simulation
    Dong-cai CHENG,Zhi-xiong HUNAG,Run-tao REN,Jing-jing WANG,Zhang-ji YE,Liang ZHANG,Yue-ping WANG
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (11): 18-25, 34.   DOI: 10.6040/j.issn.1671-9352.0.2018.031
    Abstract546)   HTML7)    PDF(pc) (2102KB)(272)       Save

    To investigate the release of the antifouling molecules in equilibrium swelling (ES) states, molecular dynamics (MD) simulation was performed to analyze the diffusion of 4, 5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) molecule in P(MMA-co-n-BMA) immersed in water. The glass transition temperature (Tg) was simulated in the dry and equilibrium swelling states, and the dynamics of water and the pendant groups in the ES state were investigated, as well as the influence of water content on the local dynamics of water. The diffusion mechanisms of DCOIT were also analyzed. Tg values of three P(MMA-co-n-BMA)s in the ES state are from 14.84, 17.27 K to 21.73 K lower than in the dry state. Water has the higher mobility than the pendant groups by approx. 2 orders of magnitude in ES systems and has dynamic properties on the same level as those of bulk water. The diffusion of a large-mass penetrant can be controlled effectively with water and Tg as the crucial factors, and the diffusion ability of DCOIT is significantly enhanced when the swollen matrix is in the rubbery state.

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    Multi-authority and revocable attribute-based encryption scheme
    LI Yan-ping, QI Yan-jiao, ZHANG Kai, WEI Xu-guang
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (7): 75-84.   DOI: 10.6040/j.issn.1671-9352.0.2017.399
    Abstract322)      PDF(pc) (1338KB)(267)       Save
    Most of the existing attribute-based encryption schemes are based on a single authority. That is, there is only one authority in the system to issue the key to the user. The curious authority will speculate the user's identity, occupation and other private information by the user's attributes. In particular, if the single authority suffered malicious attacks, it maybe cause the leakage of private key and the breach of cloud data confidentiality. In order to avoid the above two kinds of problems, multi-authority is introduced in this paper. The different authorities manage different attributes and distribute the attributes key to users, which greatly decreases the single authority's workload, improves the protection of user privacy data and solves the key escrow under a single or abuse authority. AND, OR and Threshold are flexible realized by using the access tree, and the user identity is set in the access tree to achieve the user's direct revocation. When the revocation occurs, the whole system only needs to update parts of the ciphertext without updating the attribute key, thus reducing the computational overhead of the cloud storage message. Finally, the proposed scheme is proved secure under the chosen identity attribute attack in the standard model, and the security of the scheme is built on the hardness assumption of decision bilinear Diffie-Hellman(DBDH)problem.
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    Study of dynamic of a discrete host-parasitoid model
    LIU Hua, YE Yong, WEI Yu-mei, YANG Peng, MA Ming, YE Jian-hua, MA Ya-lei
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (7): 30-38.   DOI: 10.6040/j.issn.1671-9352.0.2018.018
    Abstract430)      PDF(pc) (2085KB)(261)       Save
    A host-parasitoid model with Allee effect and Holling Ⅲ functional response function was established, and the local stability and persistence of equilibria was discussed. The influence of the Allee effect on the dynamic behavior of the model is simulated by the computer simulation and the intrinsic growth rate r as the parameter of the bifurcation diagram. We found that the introduction of Allee effect will accelerate the extinction of population in the model with both Allee effect and Holling Ⅲ functional response. When the system is strong Allee, the chaotic dynamics of the system will be reduced.
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    A secure clustering algorithm of Ad Hoc network for colony UAVs
    CUI Zhao-yang, SUN Jia-qi, XU Song-yan, JIANG Xin
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (7): 51-59.   DOI: 10.6040/j.issn.1671-9352.2.2017.258
    Abstract732)      PDF(pc) (1055KB)(261)       Save
    Colony UAVs Ad Hoc network has a large number of high speed nodes, and clustered network topology is suitable for use; a secure clustering algorithm is the base of the security of cluster structure Ad Hoc network. The characteristics and requirements for secure clustering algorithm of colony UAVs Ad Hoc network are analyzed. A secure clustering algorithm for colony UAVs Ad Hoc network is proposed. The algorithm combined cryptography and trust mechanisms to guarantee the information safety in the process of network clustering and select a cluster head with higher credibility, it is proved that it has high security and feasibility by analysis.
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    Optimal decision-making for green supply chain considering retailers fairness concern and risk aversion
    LIU Jing, ZHOU Yan, ZHENG Ying-jie, WANG Chao-sheng
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (5): 12-29.   DOI: 10.6040/j.issn.1671-9352.0.2017.268
    Abstract786)      PDF(pc) (8418KB)(256)       Save
    To study the problem of a green supply chain with uncertain demand, the game models of the green supply chain considering only retailers fairness concern, only retailers risk aversion and both fairness concern and risk aversion were constructed. The impact of retailers fairness concern and risk aversion on the optimal decisions of manufacturer and retailer as well as the overall optimal decisions of the green supply chain are studied. The results show that retailers fair concerns and risk aversion influent the optimal decisions of the green supply chain comparing with those of fair neutral and risk neutral retail. The optimal decisions, expected profits and overall profit of the green supply chain change accordingly to the degree of retailers fairness concern and risk aversion, and the trends under the various green efficiency are different.
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    Cut sets of outer P-fuzzy sets and extended rough sets models
    HAO Xiu-mei, LIU Ji-qin
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2020, 55 (10): 1-6.   DOI: 10.6040/j.issn.1671-9352.0.2020.196
    Abstract158)      PDF(pc) (384KB)(256)       Save
    The P-fuzzy sets are a pair of inner and outer P-fuzzy sets. Inner and outer P-fuzzy sets are two different kinds of dynamic fuzzy sets. The cut sets method is frequently used in fuzzy sets discussed. The concepts of λ-cut sets, strong λ-cut sets, interval cut sets and cut sets granularity are proposed, and the cut sets and interval cut sets granularity theorems of outer P-fuzzy sets are discussed. Then, the interval cut sets decomposition theorems of outer P-fuzzy sets are given. By using the concept of the outer P-fuzzy rough membership function, four rough sets extended models are proposed such as FF) rough sets, (1F,0F) rough sets, FF)probability rough sets and FF) variable precision rough sets. The FF)rough sets theorems of the outer P-fuzzy sets are discussed. In the end, the quantitative characteristics and relationship theorem are given.
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    Extraction of Chinese multiword expressions based on Web text
    GONG Shuang-shuang, CHEN Yu-feng, XU Jin-an, ZHANG Yu-jie
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (9): 40-48.   DOI: 10.6040/j.issn.1671-9352.1.2017.060
    Abstract1319)      PDF(pc) (645KB)(255)       Save
    A Multiword Expression is a kind of fixed and semi-fixed collocation in natural language, especially in network text, MWEs appear frequently, which brings a great challenge to the subsequent segmentation and text comprehension. Therefore, we propose a double-layer extraction strategy to achieve the recognition of MWEs in this paper. In the first layer, we use the LRE+EMI algorithm to achieve the initial extraction of MWEs; In the second layer, we use SVM classifier and construct the characteristics of context and word vector to classify the MWEs and non-MWEs, in order to further filter the MWEs candidate list on the basis of the MWEs candidate list got from the first layer. After the experiment, the F value of MWEs reached 84.92% in the first layer and the F value of MWEs reached 89.58% in the second layer, which have greatly improved performance compared with the baseline system. The experimental result shows that the double-layer extraction strategy can availably extract MWEs, and can effectively improve the segmentation results.
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    Pricing strategy of vehicles and cargos matching platform in the sharing economy
    Yun-miao GUI,Zhong WU,Hong-chun HU
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2020, 55 (1): 69-76,85.   DOI: 10.6040/j.issn.1671-9352.0.2019.001
    Abstract305)   HTML18)    PDF(pc) (1701KB)(247)       Save

    In order to improve the competitive advantage and performance of the vehicles and cargos matching platform, the article analyzes the characteristic of service providers of vehicles and cargos matching platform. By dividing it into professional and non-professional service providers, a game model of the vehicles and cargos matching platform is constructed. The result show that, if platforms' two sides are single-homing, the vehicles and cargos matching platform would charges the same fee for two kinds of suppliers, but if platforms' one side is multi-homing, the vehicles and cargos matching platform tend to charge high access price for non-specialist suppliers and lower access price for professional suppliers. Moreover, a strategy of accessing to suppliers firstly would be more beneficial to the oligopoly vehicles and cargos matching platform.

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    Reversible data hiding in homomorphic encrypted domain based on Paillier
    Min-qing ZHANG,Neng ZHOU,Meng-meng LIU,Han WANG,Yan KE
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2020, 55 (3): 1-8,18.   DOI: 10.6040/j.issn.1671-9352.2.2019.021
    Abstract281)   HTML123)    PDF(pc) (5044KB)(247)       Save

    Based on the homomorphism and probability characteristics of Paillier cryptosystem, a reversible data hiding in homomorphic encrypted domain based on Paillier is proposed. First, the original image is divided into blocks. The pixel groups randomly selected by the image owner have one reference pixel and eight target pixels. Least significant bits (LSBs) of reference pixel and all bits of target pixel are self-embedded into other parts of the image by a method of RDH. In order to avoid overflow when embedding data, LSBs of the reference pixel are reset to zero before encryption. The encrypted reference pixel replaces the target pixels surrounding it, thereby constructing mirror central ciphertext. In a set of mirroring central ciphertext, the data hider embeds data in the LSBs of the target pixels by homomorphic addition, while the reference pixel remains unchanged. The receiver can directly extract the extra information by modular multiplication inverse between the target pixels and the corresponding reference pixel or directly extract the secret information by plaintext subtraction and can restore the original image without loss. The experimental results show that the average embedding rate of the algorithm is 0.18 bpp (bit per pixel) under the premise of ensuring the quality of the directly decrypted image.

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    Decomposition for L2(Rn)by subspaces composed of high-dimensional tight framelet packets
    GAI Xiao-hua, GUO Xue-jun, FENG Jin-shun, CHEN Qing-jiang, CHENG Zheng-xing
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (8): 34-42.   DOI: 10.6040/j.issn.1671-9352.0.2018.058
    Abstract1203)      PDF(pc) (454KB)(245)       Save
    The decomposition for space L2(Rn)by subspaces composed of framelet packets are investigated. The characteristics of the high-dimensional wavelet frame packets with a quantity dilation matrix are described by using time-frequency analysis method and functional analysis method. The subspaces from the high-dimensional framelet packets are constructed. Moreover the direct decomposition for space L2(Rn)is obtained from these subspaces composed of framelet packets. The frequency-field formulas for the high-dimensional framelet packets are presented. A sufficient condition is suggested that a Parseval frame constituted from the high-dimensional tight framelet packets of space L2(Rn). These enrich the wavelet frame theory, so that they can be applied to a wider range.
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    Inverse spectral problem of Jacobi matrices and its application
    YU Qian-qian, WEI Guang-sheng
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (8): 66-76.   DOI: 10.6040/j.issn.1671-9352.0.2018.109
    Abstract1153)      PDF(pc) (455KB)(243)       Save
    The inverse spectral problem of Jacobi matrices is considered. A new inverse spectral theorem for Jacobi matrices with some rank 1 perturbations of the matrix Jn is proved. And the theorem is applied to the corresponding mass-spring system. The necessary and sufficient conditions for the existence and uniqueness of the solution are derived. Furthermore, the numerical algorithm and some numerical examples are given.
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    Influence of risk aversion on different types of dual-channel supply chain decision
    CHEN Liang, HU Jin-song
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (5): 30-40.   DOI: 10.6040/j.issn.1671-9352.0.2017.584
    Abstract570)      PDF(pc) (655KB)(242)       Save
    The pricing of three risk-averse dual-channel supply chains was studied. The impact of risk aversion coefficient and traditional channel sales cost on each decision variable was discussed, and the pricing strategies between different types of dual channels was compared. The results show that the risk aversion coefficient of manufacturers and retailers and sales cost of traditional channels have different effects on the optimal decision variables and market demand. Manufacturers should give priority to the vertically integrated dual-channel structure.
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    Retailer financing and ordering decision-making with limitation on the minimum loan amount
    DONG Zhen-ning, WANG Zhuo, ZHOU Xue-jun
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2018, 53 (5): 61-69.   DOI: 10.6040/j.issn.1671-9352.0.2017.366
    Abstract680)      PDF(pc) (786KB)(242)       Save
    According to the prepayment financing model, this paper establishes a bilayer structure that contains manufacturers(M)and retailers(R)and does not consider the defective product rate, inventory cost and financing cycle length. Under the conditions of uncertainty of market demand and insufficient retailers’ funds, the two retailers’ decision of financing and ordering on whether financial institutions set loan limits or not were studied. By means of numerical analysis, we verify the financing can increase the revenue of the retailer and the supplier in the case of retailers continue to accumulate their own funds, and the total supply chain product can achieve the optimum yield as soon as possible to meet the consumer’ demand effectively.
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