The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
A delayed reaction-diffusion model is established to describe the hepatitis B virus (HBV) infection and control, where the diffusion is confined to a finite domain. According to the practical meaning of the model, the equilibrium solutions of the system are derived and analyzed. Different situations of time delay and diffusion are validated by computer simulations.
This paper discussed the evaluation norm to training quality of graduate student of professional fields of the master's degree of engineering, and built up its evaluation model of fuzziness. At the end of it, a concrete example was used to explain the usage of the model.
This paper established distance education model of knowledge transmitting, which aimed at the spread characteristics of distance education network in general colleges and universities, based on the theory of complex networks. The model simulated and analyzed if it existed that individual who learned by distance education network excluded increasing of knowledge level. In the proposed model, the Cobb-Douglas...
In this paper we establish a general swarm model with time delays under disturbances for the quadratic attractant/repellant profiles. It is proved that the swarm members will converge and form a cohesive cluster around the center in a finite time under certain conditions in the presence of communication delays and disturbances. For quadratic attractant/repellant profiles, all the swarm members will...
On foundation of the comparability between tacit knowledge diffusion in project and SIR epidemic transformation, put forward that there are three kinds of project members which are knowledge holders, tacit knowledge holders and ones who give up knowledge through development it, then build tacit knowledge diffusion model in project based on ecology. According to it get critic factors which giving influence...
Supervised learning methods have been recently exploited to learn gene regulatory networks from gene expression data. They consist of building a binary classifier from feature vectors composed by expression levels of a set of known regulatory connections, available in public databases (eg. RegulonDB, TRRD, Transfac, IPA), and using such a classifier to predict new unknown connections. The input to...
Marine ecosystems are complex nonlinear systems, and there biological variables have low-dimensional nonlinear chaos characteristics. Under certain conditions, marine planktonic ecosystem can have different nonlinear dynamic properties, such as point attractor, periodic attractor as well as chaotic attractor. In this paper, a phytoplankton-fish (herbivorous) model was constructed. With the fishing...
A new method is proposed to solve multiple attribute group decision making problems with linguistic assessment information. In the method, the two-tuple linguistic representation developed in recent years is used to aggregate the linguistic assessment information. According to the traditional ideas of technique for order preference by similarity to ideal solution (TOPSIS), the optimal alternative(s)...
To deal with the problem of hostile environments, we proposed to construct heterogeneous sensor networks composed of both regular nodes and robust nodes, where robust nodes are better equipped for hostile environments and hence are more expensive than regular nodes. We study the problem of network design in heterogeneous wireless sensor networks that involves optimization of network costs associated...
Computer simulations play an increasingly important role in bio-medical research by allowing cheap verification of conjectures and exploration of ideas. The IMMUNOGRID project, among other things, has contributed to the development of computer models for the simulation of different human pathologies by adopting the agent-based modeling paradigm. In pursuing the main goal of the project, that is to...
In this paper, a three-species symbiosis Lotka-Volterra model with discrete delays is considered. The stability of positive equilibrium and the existence of Hopf bifurcations are investigated firstly and then the direction and the stability criteria of the bifurcating periodic solutions are obtained by the normal form theory and the center manifold theorem.
This article is concerned about the analysis, design, and simulation of an electric power steering (EPS). The article begins by introducing the EPS system concept and comparing the technical and commercial benefits with existing technologies. Being more versatile than conventional hydraulic power steering, EPS systems excel in engine efficiency, space saving, and environmental friendly. The remainder...
Topic discovery described here is used to determine the topic that a document or a segment discusses. It is very important for some applications of natural language processing (NLP), such as information retrieval/extraction, summarization and topic analysis etc. The paper extracts topic words based on Shannon information, in which latent Dirichlet allocation (LDA) is employed to represent word distribution...
As a new modeling thought, the accurate analytical redundancy model of power plant critical parameters was established by data mining method, which obtained effective information from the large number of real-time operation data. The basic modeling mode, including data preprocessing, mining model, verification model and the strategy from data to analytical redundancy model, was proposed in the paper...
In this paper a delayed predator-prey model system with a Holling-type IV functional response is studied. The bifurcation analysis of the model shows that a sequence of Hopf bifurcations can occur at the coexisting equilibrium as the time delay crosses some critical values. An explicit algorithm for determining the direction of Hopf bifurcations and the stability of bifurcating non-trivial periodic...
Mixed-model assembly lines typically rely in intermediate stock buffers to handle disturbances and optimize the car sequence between the main workshops in the plant. The optimization of these buffers is often constrained by installation and production specific rules. In this paper an algorithm for the stock management of buffers with drawers is proposed to handle constraints induced by the production's...
Design thinking, as a complex system, can be described as complex network. We constructed design thinking networks from analysing verbal protocols acquired form a design experiment conducted with think-aloud method. The characteristic path length and the clustering coefficient of the design thinking networks were calculated and compared with that of the equivalent random graphs. Result indicates that...
Workflow is the most widespread modeling technique application in the field of business and office information systems. In the previous paper introduced P-graph-based workflow modeling extended by the introduction of resource management is a systematic, fast method of optimal workflow model generation based on network synthesis with correct mathematical background. In this paper a further extension,...
This paper mainly discusses the control strategy for an profit-oriented ecosystem which is described by multi-dimensional Lotka-Volterra model. The though comes from the concept of impulsive control which can reach the same effect with continuous control strategy but has much more advantages while considering the feasibility factors. The difference with other impulsive control strategies is that we...
A reconstruction model of agile logistics was proposed in this paper, based on related agile and agile logistics research. At first, there was a short discussion about the agile logistics modular thinking and modular categories based on the operation of agile logistics processes, then the level of the customer service parameters and the functional modules of the logistics (transport, storage, distribution,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.