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Numerical analysis of convective heat transfer process was conducted to accurately describe the energy balance of the airfoil ice protection area. The convective heat transfer coefficient around the leading edge was calculated using four different turbulent models, including the Spalart-Allmaras model, the k-ε model, the k-ω model, and the transition SST model. Results were compared with icing tunnel...
The wings of loitering unit could be unfolded in flight. In view of the model parameters uncertainty caused by the structural change, based on the vehicle's longitudinal and lateral motion equations, combined with the characteristics of ADRC, active disturbance rejection attitude controller is designed. Six degrees of freedom nonlinear simulation model is operated with Simulink and aerodynamic parameters...
For nonlinear differential-algebraic equations system which satisfies linear growth condition and is of index one, this paper shows that there exists an appropriate sampling period such that the problem of sampled-data output feedback stabilization control can be solved. A linear explicit non-initialized observer is proposed, which means that the initial states of the observer are not necessarily...
Medical supply chain is an extremely complicated process. On basis of the perishable inventory theory, the paper mainly focuses on the optimal ordering policy of multi-pharmaceutical for the large public hospitals. The paper develops a mathematical model with constraints on space where the shortage are allowed and has a lead-time, in order to maximum the total profit of the inventory system. Then,...
An extended car-following model is proposed in this paper based on the idea of the dynamical cooperation between nearest-neighbor vehicles. The stability condition of the new model is derived by using the linear stability theory. By using the reductive perturbation method and nonlinear analysis, the modified Korteweg-de Vries (mKdV) equation are derived to describe the traffic density waves in the...
Efficient information access during emergency response not only demands fundamentally the government departments to share their data resources, but also requires an information model that implements the information flow between response agencies. This paper presents such an information model. First, four modeling elements are selected to define the information flow, which are response tasks, response...
The financial crisis occurred in the recent years has provoked managers to pay more attention to liquidity risk, especially the effect to the enterprise value. According to this, the paper gives an aspect to evaluate enterprise value from the view of liquidity. Firstly, choose indicators to describe the liquidity. Then, establish the optimization model based on the principle of relative entropy which...
Components of power systems are essentially a special class of nonlinear differential-algebraic equations subsystems, whose index is one and interconnection is local measurable. In this paper, the invertibility of power systems components is discussed. Firstly, the definition of invertibility is presented. Secondly, a recursive algorithm is proposed to judge whether the controlled components are invertable...
Quickly achieving relative states autonomous determination of space non-cooperative target is studied in this paper. Firstly, relative orbit motion states equation is established which is of high precision under condition of little distance; Secondly, united filtering algorithm of least square method and square root UKF filter is used to improve calculation precision and speed, in which least square...
Verification and validation (V&V) techniques are used in agent-based modeling (ABM) to determine whether the model is an accurate representation of the real system. Docking is a form of V&V that tries to align multiple simulation models. In a previous paper, we described the docking process of an ABM that simulates the life cycle of Anopheles gambiae. Results showed that the implementations...
On the basis of linear theory of three-dimensional piezoelasticity, the propagation of elastic waves in piezoelectric cylindrical waveguides with sectorial cross-section is analyzed. Dispersion relations in analytical forms are obtained for various boundary conditions. Numerical results including real, imaginary and complex branches of full dispersion spectra are presented to show the essential characteristics...
In this article, an approach is proposed to evaluate the reliability of Web services, where three kinds of Web services are discussed, they are atomic service without the structural information, structural activity based composite service which is composed from other services by using a structural activity mechanism, and BPEL flow process based composite service which composes all kinds of atomic...
Chemical release emergency occurred in cities easily cause large scale injuries in short time. Evacuation and shelter-in-place are two alternative response activities. In china, emergency manager usually prefer the former because many buildings are not well airtight. Also, the proportion of the residents evacuating by walk and by vehicle is high. Evacuation route has a crucial impact on the effectiveness...
Fuel optimization of fixed time hard rendezvous problem is studied. Optimal fuel is calculated by indirect and direct approaches respectively. The indirect approach is based on primer vector theory, and primer vector of transfer orbit is calculated and improved. A nonlinear optimization model is formulated for the problem of multiple-impulse rendezvous optimizing by direct approach, and the optimal...
Based on the reality of development of high-tech industry in China, this paper classified R&D input into three sources: government, enterprise and banking institutions, and analyzed effects of different source of input on technical innovation performance empirically by using Logarithmic Cobb-Douglas Production Function Model with panel data of 15 new high-tech industries from 1997-2006 in China,...
Cordyceps militaris, a kind of caterpillar fungus, has therapeutic effects including immunoregulative, anticancer, antibacterial and antifungal effects. Aqueous extraction and alkaline (NaOH) hydrolysis method were comparatively studied in polysaccharides extraction from submerged-cultured C. militaris mycelia. The results indicate that the polysaccharide content and the total extract rate from alkaline...
The static and dynamic problems of an imperfectly bonded, orthotropic, piezoelectric laminate in cylindrical bending are investigated based on the equations of piezoelasticity. A general spring layer is adopted to model the bonding imperfections at the interfaces of the laminate. The formulations of reverberation-ray analysis are developed. The approach is verified by comparing the results with those...
In this article, a user-oriented software reliability model was proposed to evaluate the reliability of Web services two kinds of Web services were discussed: atomic services without the structural information and the composite services consisting of atomic services. Firstly, the reliability of atomic service was evaluated based on an extended UDDI model. Then, the overall reliability of composite...
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