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25 July 2019, Volume 2019 Issue 4 Previous Issue    Next Issue

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Mathematics

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Characterization of commuting weakly additive maps on a class of algebras HUO Dong-hua 2019, 2019 (4):  1-10,18.  doi: 10.3969/j.issn.1000-5641.2019.04.001 Abstract ( 434 )   HTML ( 277 )   PDF (323KB) ( 469 )   Save Let A be an algebra with unit 1. A map f:A→A is a weakly additive map if for every x, y∈A there exist tx,y, sx,y∈F such that f(x + y)=tx,yf(x) + sx,yf(y). We prove that under some conditions, if f is a commuting map, then there exists λ0(x)∈A and a map λ1 from A into Z(A) such that f(x)=λ0(x)x + λ1(x) for all x∈A. As an application, a class of commuting weakly additive maps on Mn(F) are characterized. References | Related Articles | Metrics

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Oscillation of second-order generalized Emden-Fowler-type differential equations LI Ji-meng 2019, 2019 (4):  11-18.  doi: 10.3969/j.issn.1000-5641.2019.04.002 Abstract ( 401 )   HTML ( 343 )   PDF (274KB) ( 301 )   Save The oscillatory behavior of a class of second-order generalized EmdenFowler-type nonlinear variable delay neutral functional differential equations is studied in this article. By using the generalized Riccati transformation and some analytic techniques, we establish two new oscillation criteria for the equations under the condition ∫t0+∞ a-1/β(t)dt<+∞. Illustrative examples are provided to show that our results extend and improve those previously reported in the literature, and the results are both practical and implementable. References | Related Articles | Metrics

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A class of delayed HIV-1 infection models with latently infected cells YANG Jun-xian, XIE Bao-ying 2019, 2019 (4):  19-32.  doi: 10.3969/j.issn.1000-5641.2019.04.003 Abstract ( 471 )   HTML ( 268 )   PDF (366KB) ( 429 )   Save A class of delayed HIV-1 infection models with latently infected cells was proposed. The basic reproductive number R0 was defined, and the existence conditions of disease-free equilibrium P0(x0, 0, 0, 0) and chronic-infection equilibrium P*(x*, ω*, y*, v*) were given. First, the local asymptotic stability of infection-free equilibrium and chronicinfection equilibrium was obtained by the linearization method. Further, by constructing the corresponding Lyapunov functions and using LaSalle's invariant principle, it was proved that when the basic reproductive number R0 was less than or equal to unity, the infection-free equilibrium P0(x0, 0, 0, 0) was globally asymptotically stable; moreover, when the basic reproductive number R0 was greater than unity, the chronic-infective equilibrium P*(x*, ω*, y*, v*) was globally asymptotically stable, but the infection-free equilibrium P0(x0, 0, 0, 0) was unstable. The results showed that a latently infected delay and an intracellular delay did not affect the global stability of the model, and numerical simulations were carried out to illustrate the theoretical results. References | Related Articles | Metrics

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An initial-boundary value problem for the generalized Sasa-Satsuma equation on the half-line DONG Feng-jiao, HU Bei-bei 2019, 2019 (4):  33-41.  doi: 10.3969/j.issn.1000-5641.2019.04.004 Abstract ( 305 )   HTML ( 245 )   PDF (370KB) ( 446 )   Save In this paper, we implement the Fokas unified transform method to study initial-boundary value problems of the generalized Sasa-Satsuma equation on the half-line. Assuming that the solution u(x, t) of the generalized Sasa-Satsuma equation exists, we will prove that it can be expressed in terms of the unique solution of a 3×3 matrix Riemann-Hilbert problem formulated in the plane of the complex spectral parameter λ. References | Related Articles | Metrics

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Two-mode coupled KdV equation: Multiple-soliton solutions and other exact solutions ZHAO Qian, BAI Xi-rui 2019, 2019 (4):  42-51.  doi: 10.3969/j.issn.1000-5641.2019.04.005 Abstract ( 353 )   HTML ( 172 )   PDF (281KB) ( 441 )   Save In this paper, multiple-soliton solutions for a new two-mode coupled KdV (nTMcKdV) equation are obtained by using the simplified Hirota's method and the Cole-Hopf transformation. It is shown that these types of multiple solutions exist only for models in which specific values for the nonlinearity and dispersion parameters are included in the models. Furthermore, other exact solutions for an nTMcKdV equation using general values of these parameters are derived by using several different expansion methods such as the tanh/coth method and the Jacobi elliptic function method. References | Related Articles | Metrics

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Existence of entropy solutions for an elliptic equation with degenerate coercivity DAI Li-li 2019, 2019 (4):  52-61.  doi: 10.3969/j.issn.1000-5641.2019.04.006 Abstract ( 377 )   HTML ( 258 )   PDF (328KB) ( 314 )   Save In this paper, we use the truncation method to investigate the existence of solutions for degenerate elliptic problems with variable exponent in weighted Sobolev spaces. With the help of the Marcinkiewicz estimate and using some a priori estimates for the sequence of solutions of the approximate problem, and we choose suitable test functions for the approximate equation and obtain the needed estimates. Then, we obtain the entropy solutions for the elliptic equation in weighted Sobolev spaces with a variable exponent. References | Related Articles | Metrics

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Integral inequalities for generalized harmonically quasi-convex functions on fractal sets SUN Wen-bing 2019, 2019 (4):  62-71.  doi: 10.3969/j.issn.1000-5641.2019.04.007 Abstract ( 355 )   HTML ( 251 )   PDF (496KB) ( 267 )   Save In this paper, the author introduces the concept of generalized harmonically quasi-convex functions on fractal sets Rα(0 < α ≤ 1) of real line numbers and establishes generalized Hermite-Hadamard and Simpson type inequalities for generalized harmonically quasi-convex functions. Some applications for α-type special means of real line numbers are given. References | Related Articles | Metrics

Computer Science

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Second-order online portfolio selection strategy with transaction costs QU Jing-jing, YU Shun-chang, HUANG Ding-jiang 2019, 2019 (4):  72-82.  doi: 10.3969/j.issn.1000-5641.2019.04.008 Abstract ( 538 )   HTML ( 250 )   PDF (762KB) ( 428 )   Save Existing portfolio selection strategies based on the online Newton step (ONS) algorithm ignore the role of transaction costs, an indispensable factor in real markets. This paper proposes a new online portfolio selection strategy, the online Newton step transaction cost (ONSC) method, to address this issue. First, we constructed the optimal function by combining second order information of a portfolio with the transaction cost penalty term, and the portfolio was subsequently updated. Then, the sublinear regret bound O(log(T)) was achieved by theoretical analysis. Empirical research on the data sets of four real markets-namely, SP500, NYSE(O), NYSE(N) and TSE-showed that in comparison to semiconstant rebalanced portfolios (SCRP) and other strategies with transaction costs, ONSC achieves the highest accumulated wealth and the smallest turnover. Hence, the research demonstrates the efiectiveness of the algorithm. References | Related Articles | Metrics

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Design and implementation of graduate student cultivation system based on micro-services YIN Jia-ling, XIA Fan, GU Hang, ZHU Xiang, SUN Chen, WANG Ye, DONG Qi-wen, SONG Shu-bin, FU Yun-bin 2019, 2019 (4):  83-96.  doi: 10.3969/j.issn.1000-5641.2019.04.009 Abstract ( 505 )   HTML ( 223 )   PDF (2712KB) ( 500 )   Save With the development of information technology, the model of graduate student management has changed. In terms of the service target, the existing graduate student cultivation management system of East China Normal University (ECNU) was primarily targeted at school administrators. With the promotion of a "student-centered" educational concept, however, the existing system proved unable to meet student requirements. With the expansion in enrollment, the scale and growth rate of data in the systems are ever increasing. The data used by the graduate student management system has changed from a small set of simple data to a large set of complex data on teaching behavior. Based on the above reasons, ECNU has adopted an open source framework, such as AngularJS and Spring Boot, to complete the system's independent development. In terms of architecture, the system aims to use micro-services architecture to automate continuous deployment for developing an intelligent graduate student information platform that provides graduate students, teachers, and administrators with personalized services and can be quickly iterated by developers. References | Related Articles | Metrics

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User requirements oriented service recommendation for a cloud desktop GAO Zhi-qiang, YUAN Min, ZHANG Jie 2019, 2019 (4):  97-110.  doi: 10.3969/j.issn.1000-5641.2019.04.010 Abstract ( 362 )   HTML ( 25 )   PDF (1864KB) ( 417 )   Save A cloud desktop is a new type of cloud service that can provide customizable and shared resources. As a searchable cloud service, it can be configured to satisfy individual demands. This paper presents a cloud desktop recommendation method based on ontology, a description of user requirements, and matching from both resource providers and consumers. In one case, the service functions and non-functional features of a resource provider are analyzed, and ontologies are used to match user requirements with a candidate desktop image to find a reliable cloud desktop. In another case, user requirements for resource consumers are analyzed, and we utilize collaborative filtering methods to allow the user to select an appropriate cloud desktop resource, avoiding potential deviations in user resource requests. Experimental results show that the proposed method improves the accuracy of the cloud desktop in the resource discovery and selection process; moreover, the proposed method can recommend more suitable data resources according to the potential needs of users. References | Related Articles | Metrics

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An end-to-end Chinese speech synthesis scheme based on Tacotron 2 WANG Guo-liang, CHEN Meng-nan, CHEN Lei 2019, 2019 (4):  111-119.  doi: 10.3969/j.issn.1000-5641.2019.04.011 Abstract ( 896 )   HTML ( 139 )   PDF (2100KB) ( 811 )   Save The disruptively design for an end-to-end speech synthesis system Tacotron 2, is currently only available in English. This paper is devoted to implementing several improvements to Tacotron 2 and presents a Chinese speech synthesis scheme, including:a pre-processing module to convert Chinese characters into phonetic characters to address the challenge of Chinese character not corresponding to pronunciation, having multiple tones, and having polyphonic words; a pre-training decoder to achieve better sound quality with less corpus given the lack of existing Chinese training corpus; a strategy of weighting the cross-entropy loss and using the multi-layer perceptron, instead of the linear transformation, to predict stop tokens and to solve the Chinese speech synthesis sudden pause problem; and a multi-head attention mechanism to further improve Chinese speech quality. The experimental comparison of the Mel spectrum and the Mel cepstrum distance (MCD) shows that our work is effective and can make Tacotron 2 adapted to the requirements of Chinese speech synthesis. References | Related Articles | Metrics

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A distributed user-friendly Dubbo interface testing platform LI Yan-li, ZHANG Zong-yong, FENG Jie, LI Zhi-hui 2019, 2019 (4):  120-132,143.  doi: 10.3969/j.issn.1000-5641.2019.04.012 Abstract ( 595 )   HTML ( 108 )   PDF (2905KB) ( 524 )   Save With the development of online finance, the financial business has become increasingly complex and product iterations have become more frequent. Financial applications have started to use the Dubbo protocol for programming to support this prosperous business. There are some problems, however, in supporting testing of the Dubbo protocol, multiplayer collaboration, maintenance, and data analysis with the current testing tools. First, these tools can only be used to test the Dubbo protocol and the Dubbo testing framework that exists at present is difficult to promote. Second, complex businesses involve multiple applications; the current system does not consider automated collaboration among multiple systems. Third, single-machine automatic testing tools or coded automatic testing frames are not good for multiplayer collaboration in writing automatic test cases and maintenance. Finally, data analysis is usually the execution result when reviewing single-system test cases so it cannot provide a holistic analysis of data. In order to manage a large quantity test cases and support multi-system upgrades, this paper uses distribution technology to design and implement a flexible and visible Dubbo automatic testing platform with the existing testing framework. Based on an interface application, the paper provides visible data-driven and keyword-driven methods and supports the programming of complex test cases. It can also generate the interfaces that you need to test and can generate test cases according to them automatically. This paper describes the architecture of this user-friendly Dubbo testing platform and the management of test cases and execution in a detailed way. Lastly, it shows a comparison of cost vs. time and a comparison of automated test case growth between the old framework and the daily execution results of the new platform's automation testing. References | Related Articles | Metrics

Ecological and Environmental Sciences

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Experimental investigation of advanced purification of tail water in a rural sewage treatment plant of an ecological riparian zone YANG Yin-chuan, CHANG Yue-ya, CUI He, HUANG Min-sheng, HE Yan 2019, 2019 (4):  133-143.  doi: 10.3969/j.issn.1000-5641.2019.04.013 Abstract ( 436 )   HTML ( 12 )   PDF (731KB) ( 399 )   Save In this paper, four kinds of common fillers natural soil, humus soil, biological ceramist and clinoptilolite were used to design three kinds of ecologic riparian devices (R1, R2 and R3) in different mixing proportions, and the devices were all filled with ryegrass. This study explores the purification ability of different riparian zone treatment units for the tailwater of rural sewage treatment plants, and provides a scientific basis for the application of this process in engineering practice. The results showed that the removal rate of pollutants (not including NH4+-N) by R1 was significantly better than R2 and R3, and the water quality was more stable. The average removal rates of TN, NH4+-N, TP, and CODCr were 23.0%, 49.5%, 36.3%, and 25.6% respectively. The contribution of ryegrass to the removal of N and P in the tail water was 23.5% and 22.6% respectively; hence, its purification effect on tail water is confirmed. The average removal rate of NH4+-N in water containing clinoptilolite was the highest (58.2%) with R2. The genus of organisms that remove organic matter from the biofilm of the ecological riparian zone played the dominant role (eg, sphingomonas), while the proportion of bacteria for nitrogen and phosphorus removal was small (less than 2%), This indicates that the removal of organic matter in the tail water of an eco-riparian zone depends primarily on the microbial degradation and transformation of the filler, while the removal of nitrogen and phosphorus depends primarily on the adsorption of the filler and the plant. Hence, subsequent research can strengthen the function of the riparian zone according to the type of pollutants, and try to add clinoptilolite to the existing packing configuration of R1, thereby further strengthening the deep purification effect of the ecological riparian zone on the tail water of rural domestic sewage plants. References | Related Articles | Metrics

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Fuzzy comprehensive assessment of landscape water eco-compositive purifying process in Mengqing Garden XIAO Bing, YANG Yin-chuan, LU Xin-yu, LI Xin-ran, HUANG Min-sheng, YIN Chao, HE Yan 2019, 2019 (4):  144-155.  doi: 10.3969/j.issn.1000-5641.2019.04.014 Abstract ( 449 )   HTML ( 13 )   PDF (1617KB) ( 414 )   Save Located on the south side of Suzhou River, an eco-compositive purifying process is run in Mengqing Garden to treat landscape water. Single factor assessment and fuzzy comprehensive assessment (FCA) were utilized to evaluate the water quality classification, respectively. The results showed that the system reduced the concentration of NH3-N, TN and TP, with removal rates of 29.7%, 55.2%, and 24.3%, respectively, and DO was greatly elevated. The water quality fluctuated throughout the process. The water quality of the Reed Wetland was the worst, inferior to Class V and requires improved management. References | Related Articles | Metrics

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Effect of sulfide on the denitrification potential of sediment in black-odor rivers WANG Shan, ZHU Jin, HE Yan, HUANG Min-sheng, ZHOU Yun-chang 2019, 2019 (4):  156-164.  doi: 10.3969/j.issn.1000-5641.2019.04.015 Abstract ( 482 )   HTML ( 16 )   PDF (1974KB) ( 444 )   Save This study aimed to explore the effect of sulfide on sediment denitrification in different concentrations, analyze the response of bacteria, including denitrifying and sulfate-reducing bacteria, and provide a theoretical basis and technical support for improving the denitrification process of sediment in black-odor rivers. The results showed that a low concentration of sulfides (8 mg·L-1) didn't have a significant effect. In constrast, a moderate concentration of sulfides (40 mg·L-1, 64 mg·L-1) promoted the denitrification process; in this range the higher the concentration of sulfides, the faster the rate of nitrate degradation. When the sulfide concentration rises to 96 mg·L-1 and above, reductive sulfur inhibits denitrification, and the higher the concentration, the more obvious the inhibition. After a period of denitrification of the culture, the bacterial diversity is mainly composed of Proteobacteria, Chlofloflexi, and Bacillus. As the same time, the total number of bacteria in the sediment increased; the abundance ratio of nirS to 16S rRNA gene and dsrB to 16S rRNA gene were 1.42% and 0.05%, respectively. Compared with the original sediment (0.15%, 0.19%), the denitrifying bacteria increased significantly, but the number of sulfate-reducing bacteria decreased. References | Related Articles | Metrics

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Evaluation of water quality before and after treatment at Gongye River and Xiaozhai River in Shanghai LU Xin-yu, YANG Yin-chuan, XIAO Bing, HUANG Min-sheng, LI Xin-ran, YIN Chao, CAO Cheng-jin 2019, 2019 (4):  165-173.  doi: 10.3969/j.issn.1000-5641.2019.04.016 Abstract ( 362 )   HTML ( 16 )   PDF (580KB) ( 420 )   Save The water quality of Gongye River and Xiaozhai River in Putuo District of Shanghai before and after treatment were evaluated in this study. Single factor trend of dissolved oxygen, turbidity, nitrate nitrogen, chlorophyl a, and population density of zooplankton in these two rivers were analyzed; in addition, grey correlation analysis was conducted with total phosphorus, ammonia nitrogen, permanganate index, chemical oxygen demand, and five-day biochemical oxygen demand. The results showed no obvious changes in dissolved oxygen and turbidity before and after treatment. The concentration of nitrate nitrogen decreased initially after treatment. The concentration of nitrate nitrogen decreased initially after treatment, but increased thereafter, meanwhile, the concentration of chlorophyl a rose significantly after treatment. There's an increase in both species and densities of zooplankton with treatment. The grey relational analysis indicated that the water quality of the two rivers was close to Class V before treatment, reached Class I in the short term directly after treatment, and eventually stabilized at Class IV. References | Related Articles | Metrics

Estuary and Coastal Research

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A comparative analysis of the Ocean Health Index and the Pressure-State-Response evaluation methods for Shanghai's ocean ecosystem health WU Zhen, CHEN Rui-shan 2019, 2019 (4):  174-187.  doi: 10.3969/j.issn.1000-5641.2019.04.017 Abstract ( 596 )   HTML ( 16 )   PDF (1011KB) ( 515 )   Save The ocean is of great significance to humanity. It not only regulates the global climate, but it also plays a vital role in providing food, livelihood, and entertainment. The 18th National Congress of the Communist Party of China proposed:improving the capabilityfor marine resource exploration, developing the marine economy, protecting the marine ecological environment, firmly safeguarding the rights and interests of the nation's seas, and building a strong maritime nation. As one of the world's mega coastal cities, Shanghai must understand the changing trends and status of its ocean ecosystem health,and the interaction between cities and oceans. The current challenges for Shanghai's ocean coast are marine pollution, land reclamation, and typhoon storms caused by global changes. Based on evaluation methods for ocean ecosystem health, both in China and abroad, this paper compares two different evaluation methods:the Ocean Health Index (OHI) and the Pressure-State-Response (PSR). The paper evaluates the changing trends and status of Shanghai's ocean ecosystem health. The evaluation results of the two methods show that Shanghai's ocean ecosystem became healthier since 2009; it was, however,foundto be in a state of sub-standard health in 2015. The "Pressure-State-Response" (PSR) model, moreover, was found to be most suitable for Shanghai. This study provides scientific advice for the development of land and sea in Shanghai, as well as research cases for other coastal cities. References | Related Articles | Metrics

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Phosphorus content, fractionation, and desorption status in the sediments of major Chinese tidal flats CHEN Jie, WANG Dong-qi, LI Yang-jie, YU Lin, CHEN Zhen-Lou, XU Shi-yuan 2019, 2019 (4):  188-201.  doi: 10.3969/j.issn.1000-5641.2019.04.018 Abstract ( 454 )   HTML ( 13 )   PDF (2301KB) ( 458 )   Save This study analyzed the content of total phosphorus (TP) in the sediments of major Chinese tidal flats. It found that the northern flats, separated by the Zhejiang Cixi sampling site, showed low TP content in the surficial and core samples of the Liaoning Liao River delta (0.046%±0.013% surficial, 0.047%±0.015% core) and the Shandong Qingdao mud flats (0.047%±0.009%; 0.055%±0.008%). The average TP in the rest of the northern flats, such as Tianjin Hangu, the Yellow River delta, Jiangsu Yancheng, Shanghai Chongming Dongtan, and Cixi, varied from 0.051% to 0.070%, the highest level in the 12 tidal flats. Except for the Xiamen Jiulong River and Guangdong Pearl River flats (0.051%～0.070%), the TP content values were found to be lower in the southern flats, especially in Fuzhou Minjiang, Gangxi Yingluo Bay, and Hainan Dongzhaigang (0.019%～0.041%). The high TP in the northern flats can be attributed to fluvial sediments carried by high discharge rivers. At the site of high measured TP values, large amounts of Ca-P also were detected (4.16～9.56 μmol g-1). The concentration of Fe-P in the core samples was lower than the surficial samples. The tidal flats of Hangu, Qindao and Jiulong River exhibited the highest Fe-P levels. Two consecutive and non-consecutive incubation experiments showed various self-release velocities of TP. In the consecutive incubations, the largest release velocity occurred in the Jiulong River delta (0.927±0.312 μmol kg-1h-1). The non-consecutive experiments showed a significant increasing trend of TP release velocities in 11 tidal flats, except for the Liao River delta (P<0.01). Among the sites, the Hangu, displayed the highest TP release velocity (1.437±0.325 μmol kg-1h-1). References | Related Articles | Metrics

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Study on the safety of sea dikes against coastal erosion in a strong tidal estuary LI Lu, LIU Xin-cheng, SONG Yong-gang, ZHAO Geng-run 2019, 2019 (4):  202-211.  doi: 10.3969/j.issn.1000-5641.2019.04.019 Abstract ( 434 )   HTML ( 15 )   PDF (1142KB) ( 335 )   Save High resolution bathymetric data along the Huadianhuiba sea dike, a typical eroding coast on the northern coastline of Hangzhou Bay, was collected to analyze seabed evolution. A wave model covering the Changjiang Estuary and Hangzhou Bay was built to obtain the wave elements along the sea dike. Then, sensitivity analyses were carried out to calculate the impacts of coastal erosion on the wave elements, the required crest elevation, and the intensity of the seaside dike revetment. The results indicate that under a design condition of a 200 year return period with increasing water depth in front of the sea dike, the mean wave height and wave period are almost stable, while the wave length and H1% are significantly increased. The increased wave length, due to the topography deepening, is found to be a major factor for the subsequent wave run-up, which reduces the defense standard of sea dikes at crest elevation. In addition, the required intensity of the seaside dike revetment increases significantly with the depth of water in front of the sea dike. This indicates that a safety margin should be accounted for in design of the sea dike. References | Related Articles | Metrics