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    Two mixed conjugate gradient methods based on DY
    WANG Kai-rong, GAO Pei-ting
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2016, 51 (6): 16-23.   DOI: 10.6040/j.issn.1671-9352.0.2015.267
    Abstract846)      PDF(pc) (623KB)(5500)       Save
    Based on DY method, two mixed conjugate gradient methods(GDY1 and GDY2)were proposed. The search directions generated by GDY1 and GDY2 are sufficiently decent directions under some specific conditions, and are global convergence with general wolf line search. Numerical experiments show that the new methods outperform DY conjugate gradient method.
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    Semi-supervised classification based on the Markov random field and robust error function
    LIANG Jun1,2, CHEN Long2, ZHOU Wei-qi2, TAO Wen-qian1, YAO Ming2, XU Zheng-chuan3
    J4    2010, 45 (11): 1-4.  
    Abstract1175)      PDF(pc) (979KB)(3229)       Save

    A model of semi-supervised classification was proposed to overcome the problem induced by mislabeled samples. A decision rule was learned from labeled and unlabeled data,and a new energy function based on robust error function was used in the Markov random field. Also two algorithms based on the iterative condition mode and the Markov chain Monte Carlo were designed to infer the label of both labeled and unlabeled samples. Experimental results demonstrated that the proposed methods were efficient for a real-world dataset.

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    New methods for extracting emotional words based on distributed representations of words
    YANG Yang, LIU Long-fei, WEI Xian-hui, LIN Hong-fei
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2014, 49 (11): 51-58.   DOI: 10.6040/j.issn.1671-9352.3.2014.255
    Abstract1120)      PDF(pc) (3225KB)(3219)       Save
    Word-level sentiment analysis is a hot research interest in the field of affective computing. How to recognize and analyze these new emotional words automatically becomes an urgent problem. Firstly, statistics-based approach was used to identify the new words in Micro-blog corpus and then distributed representation of new words was trained by using neural network in order to get the correlation between words in corpus. Finally three vector-based methods to find new emotional words were introduced. The experimental results indicate that the proposed methods in this paper can be effectively used in discovery of new emotional words.
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    A sentiment analysis method based on a polarity lexicon
    ZHANG Cheng-gong 1, 2, LIU Pei-yu1, 2*, ZHU Zhen-fang1,2, FANG Ming1,2
    J4    2012, 47 (3): 47-50.  
    Abstract1242)      PDF(pc) (1026KB)(3129)       Save

    A polarity lexicon is the foundation of sentiment analysis and orientation analysis. An overall and effective polarity lexicon was constructed, including base lexicon, domain lexicon, network lexicon and modifier lexicon. The influence of modifiers to polarity words was studied. A sentiment analysis method based on a polarity lexicon was proposed, in which the modifiers and polarity words were combined into polarity phrases, and the phrase was used as the basic unit to compute the polarity of sentences and texts. Experimental results showed that the effect of orientation analysis using polarity lexicon raised in this paper was good.

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    The analysis of stock index sequence based on timing series model
    CUI Yu-quan, LI Pei-pei, LI Lin-lin
    J4    2013, 48 (8): 68-77.  
    Abstract616)      PDF(pc) (1320KB)(3066)       Save

    According to econometric time series model, the paper creatively proposed combing econometric model and fractal dimension based on Shanghai and Shenzhen stock market data system of great wisdom and statistical software EVIEWS during 2005-2009.It uses a high-dimensional chaotic characteristics of the stock index, using LP algorithm to determine the fractal dimension, using vector autoregressive VAR model to test unit root on the two stock markets in Shanghai and Shenzhen. According to AIC and SC information criterion, it determine the number of lags, predict the future trend of the stock market in dynamic and static state and obtain more reasonable results.

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    Elliptic curves in cryptography: past, present and future…
    ZHANG Fang-guo
    J4    2013, 48 (05): 1-13.  
    Abstract1044)      PDF(pc) (1139KB)(2455)       Save

     From the beginning of the nineteenth century, mathematicians have put the elliptic curves as a research objective of algebra, geometry and number theory to study in-depth. So far, the theory of elliptic curves applied not only in the field of mathematics, and also widely in computing science, information security, physics and other fields. In this paper, we reviewed the application of elliptic curves in cryptography, from the primality testing, integer factorization to elliptic curve cryptosystem, bilinear pairing based cryptosystem and the quantum-resistant cryptosystems from elliptic curve isogenies. We introduced the basic principles and the status of these applications. Finally, we briefly discussed some open questions and possible future progress in this area.

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    Short text classification based on word embedding similarity
    MA Cheng-long, JIANG Ya-song, LI Yan-ling, ZHANG Yan, YAN Yong-hong
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2014, 49 (12): 18-22.   DOI: 10.6040/j.issn.1671-9352.3.2014.295
    Abstract998)      PDF(pc) (2161KB)(2392)       Save
    As the short length of the Web short text and less shared words, a lot of out of vocabulary (OOV) words would appear, and these words make the task of text classification more difficult. To solve this problem, a new general framework based on word embedding similarity was proposed. First, get the word embedding file with unsupervised learning method based on unlabeled data. Second, extend the OOVs with the similar words in training data through computing the similarities of different word embeddings. The comparison with the baseline system shows that the proposed method gets better 1%-2% rate and outperforms more 10% rate on small training data set.
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    Personalized ranking of Micro-blogging forwarders
    KUANG Chong, LIU Zhi-yuan, SUN Mao-song
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2014, 49 (11): 31-36.   DOI: 10.6040/j.issn.1671-9352.3.2014.305
    Abstract699)      PDF(pc) (1411KB)(2258)       Save
    The repost action is the main way for information spreading in Micro-blogging platform. Nowadays, many works have been done focusing on the repost behaviors' analysis and prediction. However, the problem about how to find the users who are the most likely to repost a given Micro-blog remains unsolved. In this paper, a general predictor, which combines Bayesian Personalized Ranking optimization criterion with Factorization Machines was presented to predict the reposter of a microblog. Furthermore, factors which affect a user to be a reposter were analyzed in details. With these facts, prediction of the reposters over large-scale real datasets was conducted. The experiment proves that this method can improve the effect of the prediction obviously. Meanwhile, method based on pair-wise and feature-related can solve the prediction problem more efficiently.
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    An Upper Bound on the Sum of the k Largest Eigenvalues of  the Signless Laplacian Matrix of a Graph
    JIN Guang-qing, ZUO Lian-cui*
    J4    2013, 48 (8): 1-4.  
    Abstract748)      PDF(pc) (671KB)(2239)       Save

    The sum of the k largest eigenvalues of the signless Laplacian matrix of a simple connected graph is studied and an upper bound is obtained in terms of the degree sequence and the order of the graph.

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    Analysis on new word detection and sentiment orientation in Micro-blog
    TANG Bo, CHEN Guang, WANG Xing-ya, WANG Fei, CHEN Xiao-hui
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2015, 50 (01): 20-25.   DOI: 10.6040/j.issn.1671-9352.3.2014.024
    Abstract1163)      PDF(pc) (1195KB)(2124)       Save
    Due to popularity and flexibility of social media, more increasingly created words were used to express people's feelings and attitudes. New word detection and sentiment orientation has become a hot issue in Micro-blog analysis. The methods and techniques used in Task 3 of COAE 2014 were introduced. Generalized suffix tree was employed in string extraction, which was determined as new words with metrics like left-right-flexibility of words etc. Then, with pattern-based and statistic-based methods combined with multiple lexicons, sentiment orientation of new words was decided. Search engine was also used to optimize result as a supplement from semantic perspective. Results have shown our methods effective in new word detection and sentiment orientation analysis.
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    Existence of positive solutions of the m-point boundary value problem with p-Laplace operator on time scales
    FAN Jin-jun, ZHANG Xue-ling, LIU Yan-sheng
    J4    2012, 47 (6): 16-19.  
    Abstract638)      PDF(pc) (616KB)(2108)       Save

    The existence of positive solutions of the m-point boundary value problem with p-Laplace operator on time scales are considered. By using the LeggetWilliams fixed point theorem, the existence of three positive solutions is obtained. As an application, an example verified our results.

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    Sentiment classification method of Chinese Micro-blog based on semantic analysis
    YANG Jia-neng, YANG Ai-min, ZHOU Yong-mei
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2014, 49 (11): 14-21.   DOI: 10.6040/j.issn.1671-9352.3.2014.069
    Abstract902)      PDF(pc) (1943KB)(2066)       Save
    By analyzing the structural features of Chinese Micro-blog, a sentiment classification method based on semantic analysis was proposed. For the proposed method, firstly, an emoticons sentiment lexicon and a network language sentiment lexicon were built. Then by using these two lexicons and the dependency parsing results, the sentiment expression Binary Tree was constructed. Finally, the sentiment strength, which was calculated by the established rules, was applied into the sentiment classification. Experimental results show that this method is effective and two built sentiment lexicons can better enhance the performance of the sentiment analysis system.
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    Nanoporous metals: a new class of nanostructured energy materials
    DING Yi1,2
    J4    2011, 46 (10): 121-133.  
    Abstract1252)      PDF(pc) (4701KB)(2016)       Save

     Dealloyed nanoporous metals (NPMs) represent a new class of functional materials with unique structural properties such as high surface area, low density, high permeability, high electrical and thermal conductivity, and tunable structural features, which make them very attractive for important applications including catalysis, separation, and energy and environmental technologies. This article tends to provide an overview of the recent advances in this area, regarding their preparation, structure and interfacial properties. In particular, we will address their great potential as next generation electrode materials for new energy technologies.

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    The finite spectrum of SturmLiouville problems on time scales
    ZHAO Na
    J4    2013, 48 (09): 96-102.  
    Abstract596)      PDF(pc) (706KB)(1913)       Save

    In this paper, we partition the bounded time scale such that the coefficients of Sturm-Liouville problems satisfy some certain conditions on adjacent subintervals. In this case, we can construct a kind of Sturm-Liouville problems with finite spectrum on bounded time scales, and it is the extension of classical SturmLiouville problems defined on continuous intervals.

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    Schur factorization and normal matrices factorization of row (column) symmetric matrices
    YUAN Hun-ping
    Abstract1528)      PDF(pc) (186KB)(1900)       Save
    The concept of row (column) transposed matrix and row (column) symmetric matrix are given, and their basic properties are also studied. The formula for the Schur factorization and normal matrix factorization of row (column) symmetric matrix are obtained, which all can dramatically reduce the amount of calculation and Schur factorization and normal matrix factorization of row (column) symmetric matrix can save dramatically the CPU time and memory without losing any numerical precision.
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    Different game models for two-stage supply chain
    JIANG Peng-fei,SHA Ya-jun and HU Fa-sheng
    Abstract1365)      PDF(pc) (253KB)(1890)       Save
    The payoffs of manufacturer and retailer under two different bargaining game models, principal-agent game and cooperative game, are studied. The conclusion is suggested that both the players will obtain more profit by cooperating, and the consumers can also get benefit at the same time. In the cooperative game model, the K-S solution is improved and a new method of allocating total profit based on the player's distributions is introduced. The equilibrium of this game becomes more reasonable which having good directive meaning for the corporation of manufacturers lieing at the supply chain.
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    Chaos particle swarm optimization based on the adaptive inertia weight
    ZHOU Yan1,2, LIU Pei-yu 1,2, ZHAO Jing1,2, WANG Qian-long1,2
    J4    2012, 47 (3): 27-32.  
    Abstract706)      PDF(pc) (1570KB)(1884)       Save

    Aiming at the premature convergence problem which the particle swarm optimization algorithm suffers from, a chaos particle swarm optimization based on adaptive inertia weight is proposed. Firstly, chaotic sequence generated by cube map is used to initiate individual position, which strengthens the diversity of global searching. Secondly, adaptive inertia weight is adopted to improve the convergence rate. Furthermore, chaos perturbation is utilized to avoid the premature convergence. The results of the simulation experiment show that the convergence rate and the precision of the improved algorithm are obviously enhanced, and the algorithm can effectively avoid the premature convergence problem.

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    Security analysis of fast public key cryptosystem on matrix ring
    GU Chun-sheng1,2, WU Fang-sheng2, JING Zheng-jun2,3, YU Zhi-min2
    J4    2013, 48 (09): 22-28.  
    Abstract496)      PDF(pc) (750KB)(1878)       Save

    It is very important to analyze the security of fast public key cryptosystem suitable for computing devices with limited resources. By applying lattice reduction algorithm, it is not more difficult than the integer factorization problem to break the fast public key cryptosystem based on matrix ring. That is, given an oracle of factoring integers, there exists a polynomial time algorithm which solves the secret key from the public key. The correctness of security analysis is demonstrated by computational experiments.

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    Research of the text clustering based on LDA using in network public opinion analysis
    WANG Shao-peng, PENG Yan, WANG Jie
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2014, 49 (09): 129-134.   DOI: 10.6040/j.issn.1671-9352.2.2014.327
    Abstract1180)      PDF(pc) (1460KB)(1876)       Save
    For the problem that hidden information of the text may be ignored by the traditional text clustering algorithm based on words, a kind of text clustering algorithm based on the latent dirichlet allocation(LDA) topic model was proposed. The algorithm uses the TF-IDF algorithm and LDA topic model to calculate text similarity, through the cost function to determine the fusion coefficient of text similarity, through linear combination to get the similarity between texts and uses the F-measure value to evaluate the clustering result. In the constructing of the LDA model, the algorithm uses Gibbs sampling to estimate the parameter, and through the Bias statistical standard method to determine the optimal number of topics. Viewing from the accuracy and stability of clustering results, the simulation results show that the proposed algorithm has a better effect than the traditional text clustering algorithm.
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    Measuring user influence of a microblog based on information diffusion
    GUO Hao, LU Yu-liang, WANG Yu, ZHANG Liang
    J4    2012, 47 (5): 78-83.  
    Abstract640)      PDF(pc) (832KB)(1875)       Save

    Information diffusion and influence modeling are hot topics in microblog research. To do research on influence quantitatively, a concept based on the message diffusion was introduced and complied with how to count it out. The proposed approach was validated on real world datasets, and the result of experiments shows that our method is both effective and stable, especially in condition of limited dataset and time span.

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    A method of personalized privacy preservation based on K-anonymization
    KANG Hai-yan, YANG Kong-yu, CHEN Jian-ming
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    2014, 49 (09): 142-149.   DOI: 10.6040/j.issn.1671-9352.2.2014.320
    Abstract781)      PDF(pc) (3365KB)(1853)       Save
    Aiming at the shortcomings of the global and local algorithms of the privacy preserving in data publishing, a method of top-down personalized generalization backtracking algorithm and its expansion algorithm based on the K-anonymous were proposed. The method combines the L-diversity and (s, d)-anonymization and dynamically build generalization tree structure, by which users can customize the privacy security levels and separate the similar level of safety as far as possible, so as to guarantee the availability and security of the information, which can effectively prevent homogeneity attack and background knowledge attack. Based on the above thinking. A system of personalized privacy preservation based on K-anonymization was developed on J2SE platform. The comprehensive experimental data shows that the algorithm can improves security and guarantee the availability of information effectively.
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    Asymptotics for the LASSO estimator for partially linear models
    LI Feng1, LU Yi-qiang2
    J4    2012, 47 (3): 93-97.  
    Abstract778)      PDF(pc) (908KB)(1827)       Save

     Based on the profile least squares method, the LASSO penalty profile least squares estimator is constructed, and the choices of penalty parameter and bandwidth are also discussed. Because the optimization problem is linear, it can be easily implemented. Under some regular conditions, the consistency and asymptotic normality of the estimator for parameter component are investigated. Finally, Monte Carlo simulation studies are conducted to assess the finite sample performance of the proposed variable selection procedures.

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    Global exponential robust stability of stochastic interval cellularneural networks with S-type distributed delays
    ZHANG Wei-wei1, WANG Lin-shan2*
    J4    2012, 47 (3): 87-92.  
    Abstract693)      PDF(pc) (1296KB)(1812)       Save

    By applying the Lyapunov stability theory and stochastic analysis approaches, some algebraic criteria are derived to ensure the globally robustly stochastically exponentially stability in the mean square for the addressed system, and the almost sure exponential stability is also studied. An example is given to illustrate the effectiveness and improvement over existing results.

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    Advances of gene knockout in mice
    ZHANG Jian, YANG Xiao-mei*, GAO Jian-gang*
    Abstract1099)      PDF(pc) (1176KB)(1800)       Save

    With the successful completion of Human Genome Project (HGP),the biological research of postgenome era has a urgent need for an effective gene function analysis. Application of knockout mouse model provides a strong support for the study of gene function and the search for new therapeutic interventions in human disease. As two different techniques, gene targeting and gene trapping are producing knockout mice from embryonic stem cells (ES cells).The characteristic of gene trapping is highthroughput, random, and sequence tagged,while gene targeting is a specific gene knockout. Two decades ago, the first gene targeting and gene trapping mice were generated. In recent years, new tools for gene targeting and gene trapping are emerging, and the related organizations have been formed. These organizations can knock out genes in the mouse genome using these two methods. The international gene trap consortium (IGTC) and the knockout mouse project (KOMP) have begun to create a worldwide resource for research facilities, and plan to knock out all the mouse genes. KOMP organizers consider it as important as the HGP. From conventional gene targeting to high throughput conditional gene targeting, gene targeting methods have changed. The combined advantages of trapping and targeting enhance the gene trapping spectrum and gene targeting efficiency. As a newly developed insertional mutation system, transposons in trapping genes have more advantages than retrovirus. Emergence of the international knockout mouse consortium (IKMC) is the beginning of global cooperation. The organization is committed to systematically knock out all genes in the mouse genome, and then to carry out functional genomics studies.

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    First principles study of structure and thermodynamic properties of MgH2
    LIU Fu-ti1,2, CHENG Xiao-hong2, ZHANG Shu-hua3
    J4    2012, 47 (1): 39-43.  
    Abstract792)      PDF(pc) (2282KB)(1797)       Save

    Based on the first principles electronic structure and thermodynamic properties of tetragonal MgH2 with pressures up 100GPa and temperatures up to 600K were studied with a quasi-harmonic Debye model. The volumes, equilibrium lattice parameter, energy gap were obtained, and the bulk modulus, heat capacity and entropy, Debye temperature and volume thermal expansion coefficient under different pressures and temperatures were successfully calculated.

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    Automobile domain oriented spam detection
    TANG Du-yu1, WANG Da-liang2, ZHAO Kai2, QIN Bing1, LIU Ting1
    J4    2012, 47 (3): 43-46.  
    Abstract807)      PDF(pc) (918KB)(1786)       Save

     The task that aims to detect spam reviews for the automobile domain was divided into four sub-tasks: supporting review detection, irrelevant review detection, advertisement detection and fake review detection. Both rule-based methods and machine learning methods were used to identify spam reviews. Many aspects were considered in the rule-based method, such as automobile domain knowledge, words with polarity, and information of the author. The review content feature and author information were combined to train a model with a maxent classifier. Experimental results showed that machine learning method performs well for the domain whose property was obvious, with numerical feedback information and labeled training data.

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    A novel analytical essential matrix decomposition algorithm#br#
    WU Chun-fu1, TANG Qing-shun1, XIE Huang-sheng1, ZHOU Feng-yu2*
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)    DOI: 10.6040/j.issn.1671-9352.0.2014.002
    A kind of adaptive species optimization of wireless Mesh network QoS routing algorithm
    WAN Zhi-ping1, L Zhi-min1,2 *
    J4    2013, 48 (09): 10-16.  
    Abstract397)      PDF(pc) (1466KB)(1772)       Save

    For the network latency that is caused by the inequalities of wireless Mesh network bandwidth and load energy, and low operation speed of the routing algorithm and so on, a kind of adaptive species optimization of Wireless Mesh Network QoS routing algorithm (AQPSO) was proposed. To avoid the transmission delay and congestion of the data, the algorithm uses route evaluation function to search the best node path and through ant pheromone updating rules to balance the network load. Meanwhile, combined with the speciation policy of quantum behavior particle swarm optimization algorithm, a best position field adaptive search pattern was put forward, which improved the convergence speed of the algorithm. Viewing from the network latency and the algorithm convergence speed, the simulation results show that the proposed algorithm has a better effect than the improved ant colony QoS routing algorithm and QoS routing algorithm based on genetic algorithm.

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    Determination of melamine in eggs by high performance liquid chromatography
    WEI Jin-mei, ZHANG Yong-mei, CAO Lu-xing, LUO Yu-zhu*
    J4    2010, 45 (5): 19-21.  
    Abstract842)      PDF(pc) (627KB)(1760)       Save

    A method was reported for the determination of melamine in eggs. After being extracted by 1%Trichloroacetic acid solution and 2.2% lead acetate from samples,melamine was separated on a Hypersil ODS 100×4.6mm,5μm C18 column with a volume ratio of acetonitrile and sulfonic sodium octane(pH=3) of 15∶85,  and  was detected by an ultraviolet detector at a wavelength of 210nm.The temperature of column was 40℃. The linear ranges were from 0.2μg/mL to 10.0μg/mL. The results indicated that the average recoveries were 82.0%~104.0% for high, middle and low concentration levels by this method. The relative standard deviations RSD was 6.81%(n=9).

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    The instance of new drug research and development: novel anti-cancer lead compounds of 4-thiazolidinones
    LIU Xiao-jun1, YAN Bing2*
    J4    2010, 45 (5): 1-5.  
    Abstract914)      PDF(pc) (1165KB)(1759)       Save

    Taking thiazolidinone compounds as an example, we discuss the processes leading to the discovery of anti-cancer lead compounds. Using combinatorial chemistry and high throughput screening approaches, we discovered potent compounds against drugresistant cancer cells. Mechanistic studies indicated that these compounds inhibited microtubule formation, caused G2/M arrest in cell cycle, and induced apoptosis and autophagy. The anticancer activity did not depend on the status of P-gp in cells. These compounds had superb membrane permeability and inhibited tumor growth in vivo. Screening them against 60 human cancer cell lines demonstrated broad anti-cancer activities indicating that they will play a significant role in the future of our fight against cancer.

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    A user-centric identity management and authentication system for mobile Internet
    WANG Juan1,2, HE Qi1, YAN Fei1,2, JIANG Wan-wei1, YANG Ming1, WANG Yan1
    J4    2012, 47 (11): 12-17.  
    Abstract585)      PDF(pc) (1194KB)(1747)       Save

    Based on the current research of user-centric identity management mechanism and technology, a new user-centric identity authentication system on mobile Internet platform named ID-Vcard was proposed and implemented on the Android platform. In the system of ID-Vcard, user can manage and use own identity information in the form of virtual card. In the process of authentication, it takes the advantage of the user’s and IdP’s digital certificates to authenticate users on RP. ID-Vcard has good usability in mobile platform because users can manage their identity information by virtual cards. In addition, it tries to reduce and eliminate the username/password authentication method.

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    Improved certificateless aggregate signature scheme
    HOU Hong-xia1,2, ZHANG Xue-feng2, DONG Xiao-li2
    J4    2013, 48 (09): 29-34.  
    Abstract599)      PDF(pc) (693KB)(1745)       Save

    Recently, the aggregate signature is a hot topic concerned. An improved cerificateless aggregate signature scheme is constructed based on the certificateless cryptography. Compared with the existing schemes, the scheme has constant pairing computations, and the verification algorithm only requires three pairing computations, which greatly improves the efficiency of the signature verification. The improved scheme can resist the attack of TypeⅠand TypeⅡadversary in certificateless adversary model,and it is existentially unforgeable under the computational DiffieHellman assumption.The security proof of the improved scheme is given in the random oracle model.

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    A new method of solving the assignment problem based on the permissible-edge algorithm of minimum cost flow problem
    XIONG De-guo, HU Yong-wen
    J4    2012, 47 (3): 103-109.  
    Abstract691)      PDF(pc) (2190KB)(1734)       Save

     A new algorithm of the assignment problem is proposed by constructing its minimum cost maximum flow model and applying the permissible-edge algorithm based on the principle of duality to the model. The new algorithm gradually expands the permissible network in the capacity-cost network by means of modifying the potential of labeled nodes subject to complementary slackness condition, and then augments flows on the permissible network, which proceeds until the minimum cost maximum flow of the original capacity-cost network is obtained. The non-zero edge of this maximum flow corresponds to the optimal solution of the assignment problem. During the iterating process, successive iteration will fully use the information of previous ones, which effectively reduces the computation. For non-standard assignment problems, this algorithm can be directly applied without converting the problem to the standard form.

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    Soft Boolean algebra
    LIU Wei-feng
    J4    2013, 48 (8): 56-62.  
    Abstract587)      PDF(pc) (626KB)(1722)       Save

    The soft set theory is applied to the Boolean algebra. The concepts of soft Boolean algebra, soft Boolean subalgebra, soft ideal of soft Boolean algebra and idealistic soft Boolean algebra are presented and some related algebraic properties are discussed. The relations between soft Boolean algebra and several kinds of fuzzy subalgebras of Boolean algebra are preliminarily investigated.

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    Morita context rings with a pair of zero homomorphism
    WANG Xiu-jian1,2, CHENG Zhi1, DU Xian-neng1*
    J4    2013, 48 (6): 42-45.  
    Abstract529)      PDF(pc) (656KB)(1717)       Save

    A sufficient and necessary condition that a Morita context ring T is a VNL ring is given by introducing the definition of the pair of partial modules. The properties that Morita Context rings are left Quasi-duo rings, DS rings and left Quasi-morphic rings are also characterized.

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    Research on source location privacy routing based on angle and probability in wireless sensor networks
    ZHAO Ze-mao1, LIU Yang1, ZHANG Fan1,2, ZHOU Jian-qin1, ZHANG Pin1
    J4    2013, 48 (09): 1-9.  
    Abstract451)      PDF(pc) (2004KB)(1705)       Save

    In wireless sensor networks(WSN) source location privacy protection issues, aiming at hop by hop backtracking attacker with the ability of local traffic analysis, a source location privacy routing protocol RAPFPR based on random angle and probability forwarding is proposed. The protocol is mainly divided into two phases: the true source node according to the random angle and distance directed routing phase and the phantom node to the base station based on probability forwarding routing phase. The protocol of the phantom nodes can evenly distributed around the true source node, and probability forwarding routing greatly reduces the probability of overlapping path,increased the difficulty of hop by hop reverse attacker. Compared with the existing privacy protection scheme, simulation results show that under the premise of without significantly increasing the communication overhead, this protocol can effectively prolong the average network safety time and has a very good privacy protection performance.

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    A new method for localization based on network  coverage and intelligent search
    ZHOU Shu-wang1,2,3, WANG Ying-long1,3, GUO Qiang1,2, WEI Nuo1,2, GUO Wen-juan1,3
    J4    2010, 45 (11): 27-31.  
    Abstract844)      PDF(pc) (986KB)(1700)       Save

    A new method for localization based on network coverage and intelligent search (CIL) was presented. First, the distance from each anchor nodes to the unknown node was used to determine the possible region. Second,  the positions which meet specific criteria were searched out by a particle swarm optimization algorithm, and the searching results within the possible region were recorded. Finally, the unknown node′s localization could be obtained by calculating the average recording results. Experimental results showed that CIL has high positioning accuracy and strong robustness. Compared with normal schemes such as the least square method (LS), the CIL′s positioning accuracy could improve 49% when the ranging error was 35%.

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    Reflected BSDEs with a stochastic Lipschitz coefficient
    LV Wen1,2
    J4    2011, 46 (6): 79-83.  
    Abstract785)      PDF(pc) (306KB)(1698)       Save

    A class of reflected backward stochastic differential equations with a stochastic Lipschitz coefficient is considered. First, the existence and uniqueness of the solutions for those equations in a special form are proved via Snell envelope. Then the same result for those equations in general form is obtained by using the fixed point theorem.

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    On non-admissible meromorphic solutions of systems of  non-linear complex algebraic differential equations
    SU Xian-feng, LI Xiao-meng
    J4    2012, 47 (8): 39-41.  
    Abstract556)      PDF(pc) (659KB)(1666)       Save

     By the theory of Nevanlinna′s value distribution, it is proved that the meromorphic solutions of a type of systems of non-linear complex algebraic differential equations are non-admissible.

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    Tracking event microblogs: a streaming dynamic topic model
    SHI Cun-hui, LIN Hong-fei*
    J4    2012, 47 (5): 13-18.  
    Abstract835)      PDF(pc) (846KB)(1664)       Save

    In order to solve problems which include the topic drift phenomenon and much higher level of noise in micro-blogs, an algorithm named the Streaming Dynamic Topic Model, which improves the dynamic topic model with MEntropy, was presented to track additional events on topics. The method of the dynamic topic model was  first tried to update the topic in the whole tracking process, which enhanced the description power of the topic model by both positive and negative sides to overcome the topic drift problem. However, as a high level of neutral posts existed, MEntropy was defined and used to evaluate the importance of a microblog for tracking a topic, and was then extended to the dynamic topic model in order to make   a better distinction between even microblogs and neutral ones. Topic tracking experiments on a collection of more than 170,000 users’ 12 million microblogs show that our algorithm is more efficient and with lower noise compared with the traditional dynamic topic model.

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