Papers by Keyword: Parameter

Abstract: The paper starts from performance optimization of Oracle database. Based on analysis of Oracle structure, the paper explores performance optimization of Oracle database for database parameters, application system and network load. And the paper expounds reasonable planning of database and how to analyze and improve the performance after operation, and how to optimize a database with satisfying performance.

Abstract: To explore effective methods of avoiding POGO instability, this paper starts with a thorough study on influence of parameters on natural frequency of propulsion system in liquid rocket. By adopting the method of critical damping ratio, stability of coupled structure-propulsion system is analyzed. The results show that installing an accumulator in suction line can effectively decrease natural frequency of propulsion system, which can improve the stability of coupled system. When cavitation and inertance of accumulator increases or installation position gets closer to top of pump, the influence of accumulator on the natural frequency becomes more significant.

Abstract: Aiming at a kind of special object with fractional characteristics,a new kind of fractional order PI^λ-PD^μ controller is put forward in this paper,In this control system, the forward channel of system contains a fractional order PI^λ controller,while the feedback loop adopts PD^μ controller.The control structure in this fractional order system can achieve a good performance of the closed loop control.Moreover,the impacts on system dynamic performance and static performance are compared when the parameters in the controller are changed.The results show that when these parameters are in the reasonable range,the system can achieve better control performance.

Abstract: The main ideas of optimization technique for allocation scheme and hydro power plant (HPP) parameters with respect to regional peculiarities are described in the article. The problem is discussed using rivers channel network. Energy, economic, social, ecological, water-energy and resource specific regional peculiarities are taken into account. Rivers channel network water energy cadastre calculations have been formalized. Algorithm for hydro power plant optimal location search and HPP number at rivers channel network have been developed. Main hydro power plant parameters are substantiated for each of numerous location variants based on formalized water energy calculations.

Abstract: This Paper Aims from the Simulation Tests to Highlight the Influence of the Diameter and Material Quality, Reflected by the Flow Limit of the Pipe and the Quality and Technological Parameters at the Bending under Pressure of the Pipes. from Literature, those Quality Parameters which Characterize a Correct Bending are: the Ovality of the Transversal Section, the Variation of the Wall Thickness or Eccentricity, the Lack of Whetstones, the Resistance in Function of the Bent Pipe. Pipe Material Characteristics Influence the Quality Parameters of the under Pressure Modeling Process, in the Sense that at the Materials with Small Flow Limit, Ovality or Variation of the Wall Thickness are Small. at Pipes under Pressure Modeling, Ovalities and Variation of the Wall Thickness are in Permissible Limits Valid Recommended for Domains without Special Precision Restrictions.

Abstract: This paper is a result of a research focused on statistical vehicles dynamics. Its main purpose is to establish mathematical description of vehicle dynamics based on statistically sufficient experimental data and using statistical instruments. The results are analytical expressions and graphical representations that can be used in situations other than those the data were obtained. Experimental research program objective was to obtain a variety of data to define the dynamics of a vehicle. It involved a large number of tests, more than 100, on different runways, pavement, mosaic tiles or asphalt. They were performed in various weather conditions, sunny and warm weather or rain or sleet and snow. The driving style varied between normal and sport ones. The experimental data were used in obtaining mathematical models that define certain dependency between dynamic parameters. There were issued multiple linear regressions with one resulting parameter. If we analyzed the models we issued we notice that the more factorial parameters are involved, the higher the accuracy of the model we get.

Abstract: In the paper stated method that is grounded on the following idea, firstly applied in the work [1]. The critical state equation of compression plate is obtained from according equations of lateral bending of same plate, if is made the substitution -P=T10Wx''+2S0T10Wxy''+T20Wy'' where T10, S°, T20-are the components of external compressive loading. Further the obtained differential equations are transferred into algebraic equations by approximation of deflection by system of preliminary selected functions and application of one of variation methods. From the obtained algebraic equations are defined the parameters of critical loading. The applied in the work method is that firstly is solved the static problem and are found deflection functions, subjected to concentrated loading in the point x=ξ, y=η, corresponding for al singularities, arising due the cuts influence. Actually at this are found the Green’s functions. This task is solved analytically and due the application of special discontinuous functions, the function of deflection is expressed as rapidly convergence series. Practically for the definition of deflection is sufficient the keeping of one term of series. Due the stated above [2] also is considered the solution in the refined formulation. The definition of critical loading on three-layered plate on grounded on the accordingly static problem.

Abstract: Unreasonable parameters may lead to a phenomenon of the numerical instability in evolutionary structural optimization method (ESO). In this paper the improved SIMP-based ESO method for the structural compliance sensitivity is presented to solve the problem of checkerboard pattern. The method depends on the sensitivity analysis results that indicate the contribution of each unit for the whole structural performance to delete and to add elements. At the same time, the method in combination with a sensitivity redistribution technology of controlling checkerboard pattern is used to realize that each element’s contribution or impact factor of the whole structural performance has a smooth transition. The instance shows that the method is reasonable and different parameters will affect the optimized results. The optimal values of parameters can be seen obviously finally.

Abstract: A country's level of Nc machine tool and ownership, is to measure the level of manufacturing and industrial modernization level of important indicators, is also an important index to measure national comprehensive competitiveness. Therefore, how to better use and maintenance of Nc machine tool is an important issue. This paper introduced how to reasonable use of Nc machine tools, as well as the use of the numerical control system and inspection.

Abstract: The terminal uses data acquisition module to collect antenna parameters of the base station, data is processed by S3C2440 core module and transmitted to management system by wireless communication module. This introduces hardware and software design solution of the terminal. The intelligent terminal can measure coordinates, altitude, azimuth and tilt of base station.