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Search Results: 1 - 10 of 81797 matches for " Lili Liu "
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Interaction Mechanism and Strategy of Brand Relationship and Brand Extension  [PDF]
He Liu, Lili Fan
Open Journal of Business and Management (OJBM) , 2013, DOI: 10.4236/ojbm.2013.13008
Abstract: As new products are generally difficult to be accepted by consumers, and the cost of initial market introduction is high, enterprises often choose to do market extension of an existing brand. Simultaneously, a successful brand extension can enhance the reputation of the original brand, and expand the brand value. But how can enterprise take a good brand extension? Through establishment of a dynamic model of brand extension under the brand relationship context, investigating the interaction mechanism between brand relationship and extension, and base on that, we developed a strategy model of interaction and improvement of brand relationship and brand extension.
An Evaluation of the Operation of the Railway E-Ticketing System  [PDF]
Lili Fan, Xinhua Liu, Jianwen Wang
iBusiness (IB) , 2012, DOI: 10.4236/ib.2012.42019
Abstract: In this paper, the operation smooth of the railway computer ticket system was evaluated. First, we design the evaluation index system, determine the subjective weights of the various technical indicators of the ticketing system with Fuzzy evaluation method, determine the index weight with the Entropy method, and analyze important factors affecting the system operation according to the health evaluation results of the ticketing system over the years.
Performance Research on Magnetotactic Bacteria Optimization Algorithm with the Best Individual-Guided Differential Interaction Energy  [PDF]
Hongwei Mo, Lili Liu, Jiao Zhao
Journal of Computer and Communications (JCC) , 2015, DOI: 10.4236/jcc.2015.35016
Abstract:

Magnetotactic bacteria optimization algorithm (MBOA) is a new optimization algorithm inspired by the characteristics of magnetotactic bacteria, which is a kind of polyphyletic group of prokaryotes with the characteristics of magnetotaxis that make them orient and swim along geomagnetic field lines. The original Magnetotactic Bacteria Optimization Algorithm (MBOA) and several new variants of MBOA mimics the interaction energy between magnetosomes chains to obtain moments for solving problems. In this paper, Magnetotactic Bacteria Optimization Algorithm with the Best Individual-guided Differential Interaction Energy (MBOA-BIDE) is proposed. We improved interaction energy calculation by using the best individual-guided?differential interaction energy formation. We focus on analyzing the performance of different parameters settings. The experiment results show that the proposed algorithm is sensitive to parameters settings on some functions.

Role of Time-Domain Based Access Control Model  [PDF]
Chaoqun Liu, Zhen Peng, Lili Wu
Journal of Software Engineering and Applications (JSEA) , 2016, DOI: 10.4236/jsea.2016.92004
Abstract: While Role-Based Access Control Model (RBAC) is being analyzed, the concept of Role of Time-domain Based Access Control Model (T-RBAC) is put forward. With time-domain added, both time-domain and authority control roles. The basic idea of T-RBAC is introduced and described formally, and the safely of this model is analyzed. The research shows that T-RBAC fulfills both rules of information security, which are principle of least privilege and separation of duties. With practical application of T-RBCA, it can handle most of the time-related or authority-related problems. What’s more, it also increases the security level, flexibility and dynamic adaptation of the system and has lower complexity than system only handled by authority. This model also can solve conflicts caused by authority.
Asymptotic Behaviors of a Delayed Nonautonomous Predator-Prey System Governed by Difference Equations
Lili Liu,Zhijun Liu
Discrete Dynamics in Nature and Society , 2011, DOI: 10.1155/2011/271928
Abstract: Based on a predator-prey differential system with continuously distributed delays, we derive a corresponding difference version by using the method of a discretization technique. A good understanding of permanence of system and global attractivity of positive solutions of system is gained. An example and its numerical simulations are presented to substantiate our theoretical results. 1. Introduction It is well known that the classical Lotka-Volterra differential equations for predator-prey interaction can be written as where , , , and are the population densities of prey and predator, respectively, at time , and the coefficients are positive constants. is the intrinsic growth rate of prey species, and represents the death rate of predator species; and , denote their self-inhibition and interaction rates, respectively. To account for time lag effects in their interaction, Cushing [1] suggested visualizing system (1.1) as a special case of the following more general system where are nondecreasing functions on with for each , and with , respectively, equal to for . As Hale [2] pointed out, one expects that the lag effects tend to diminish gradually in ever-moderating pace as one moves backward in time after the initial instantaneous effect described by the assumption . The effects are negligible after a certain length of time . Mathematically, for , it is reasonable that can be assumed to be of the form , , where and continuous for ; for ; and continuous for ; and both exist; and continuous for . The assumption represents gradual diminishing effect as one moves backward in time, and the assumption stands for the moderating pace of the decrease (see [2] or [3] for the assumptions to ). Leung [4] revised system (1.2) and established the following predator-prey model with continuously distributed delays The parameters of system (1.3) are assumed to be constant; however, in the real world the parameters are not fixed constants owing to the variation of environment. The effect of a varying environment is significant for evolutionary theory as the selective forces on systems in a fluctuating environment differ from those in a stable environment. Thus, it is realistic to assume that the parameters of system (1.3) are continuous functions with respect to , and then we obtain the following form: where the coefficients are positive continuous functions and satisfy for . Although much progress on the predator-prey models with discrete or distributed delays has been made, such models are not sufficiently researched in the sense that most results are continuous time
Numerical Calculation of Viscous-Elastic Fluid Flooding Residual Oil Film in the Complex Pore  [PDF]
Lili Liu, Chao Yu, Lihui Wang, Lu Liu
Open Journal of Fluid Dynamics (OJFD) , 2013, DOI: 10.4236/ojfd.2013.33019
Abstract:

In order to analyze the stress and deformation of different permeability of residual oil film in the complex pore, which are affected by the viscous-elasticity of the fluid, the hydrodynamic displacement mechanism is explored from the stand-point of hydrodynamics, that is, the residual oil film displaced by alternating injection of different concentrations of the polymer solution, viscous-elastic fluid flow equation is established in the complex pore by choosing continuity equation, motion equation and the upper convected Maxwell constitutive equation. The flow field is computed by using the method of numerical analysis. Not only the stress and deformation of residual oil film on the different permeability of micro pores, but also the analysis of the flooding mechanism of alternating injection of different concentrations of the polymer solution is got. The results show that the larger the viscous-elasticity of polymer solution is, the bigger the normal deviatoric stress acting on the residual oil film is; the distribution of normal deviatoric stress has the abrupt change. The stronger the viscous-elasticity of the polymer solution is, the bigger the horizontal stress difference acting on the residual oil film is and the more obvious the deformation is; the high-concentration polymer solution is suitable for high-permeability micro pores. Low-concentration polymer solution is suitable for medium and low-permeability micro pores. Alternating injection of polymer solution can improve

Analysis of chemical composition of precipitationin a typical background site
Liu Jiaqi,Shi Lili
环境科学学报(英文版) , 1998,
Abstract: A background precipitation in Lijiang, China was investigated. Results showed that the chemical composition of atmospheric background precipitation mainly comes from fly ash and continental atmospheric transfer, and does not have any obvious correlation with oceanic aerosol, taking Amsterdam in the Pacific Ocean and St. Georges in the Atlantic Ocean and Katherine, Australia as examples for analysing. 
Fractionation and structural identification of antibiotic activity substances from Streptomyces herbaricolor HNS2-2  [PDF]
Lili Chen, Youzhi Li, Hongjian Zhu, Yuhua Liu, Bida Gao
Agricultural Sciences (AS) , 2012, DOI: 10.4236/as.2012.34068
Abstract: Four groups of antibiotic activity compounds were separated and purified from the ethyl acetate fraction of a broth culture of Streptomyces herbaricolor HNS2-2.Trace analyses were performed and anti-microbial activities were determined. The antibiotic activity compounds were identified as quercetin dehydrate ①, p-hydroxyphenyl ②, 4’-hydroxyflavanone ③, and 3-hydroxyflavone ④ based on spectroscopic data. Compounds 1-4 showed significant antimicrobial activities against Staphylococcus aureus and the tobacco mosaic virus in vitro, suggesting their potential agricultural and medical applications.
Design and Implementation of Embedded Web Server in Industrial Control Systems  [PDF]
Jianming Liu, Jincai Wang, Yunjie Zhang, Lili Xu
Communications and Network (CN) , 2013, DOI: 10.4236/cn.2013.51B015
Abstract: In the traditional project of industry control, the field operator is the only man who watches production condition at the production spot. Enterprise administers cannot obtain real-time production status and make real-time decision if they don’t reach the production spot. Because of the development of Embedded Web Server such status is being changed. The remote monitor and control mode based on Embedded Web Server provides complete exact real-time information for managers, and makes it possible to make a decision in real time. In the paper, the design and implements of Embedded Web Server are presented and the key realization technology of it is described in detail. EWS (Embedded Web Server) will effectively lower system operating cost and improve maintaining efficiency, which has wide application prospect and popularization value in industrial control systems.
Mechanical Analysis of Viscous-Elastic Fluid Acting on Residual Oil in the Micro Pore  [PDF]
Lili Liu, Chao Yu, Lihui Wang, Chengchuyue Fu, Peixiang Li
Open Journal of Fluid Dynamics (OJFD) , 2013, DOI: 10.4236/ojfd.2013.34030
Abstract: In order to analyze the normal deviatoric stress that viscous-elastic fluid acting on the residual oil under the situation of different flooding conditions and different permeabilities, Viscous-elastic fluid flow equation is established in the micro pore by choosing the continuity equation, motion equation and the upper-convected Maxwell constitutive equation, the flow field is computed by using numerical analysis, the forces that driving fluid acting on the residual oil in micro pore are got, and the influence of flooding conditions, pore width and viscous-elasticity of driving fluid on force is compared and analyzed. The results show that: the more viscous-elasticity of driving fluid increases, the greater the normal deviatoric stress acting on the residual oil increases; using constant pressure gradient flooding, the lager the pore width is, the greater normal deviatoric stress acting on the residual oil will be.
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