Mathematical Mode Research Articles

Error Analysis of Improved Current‐Bridge Method for Accurate Low‐Impedance Measurement

SUMMARYThe improved current‐bridge method and its mathematical mode are proposed for accurate low‐impedance measurement. To realize the accurate measurements of shunt resistors smaller than 1 mΩ, the expansion of current ratio of a current transformer and a current comparator, the use of low‐value resistance for reference impedance, and the development of a buffer amplifier which have flat load characteristics are required. The improved current bridge‐method has the possibility for accurate measurement of shunt resistors up to 10 μΩ.

Local surface plasmon induced fluorescence emission enhancement and its application in white light emitting diodes

Local electric enhancements of phosphors induced by the surface plasmon polariton of metallic particles are analysed in detail. Applying mathematical mode, the resonance absorption peak of Ag and Au particles with optimal sizes and distances are determined to couple the typical emission wavelengths (450nm, 515nm and 630nm) of white light emitting diodes. The effects of size uniformities, errors of distances to the fluorescent emitting center and the broadening of excitation spectrum on local electric enhancement are also evaluated, and the results show that the prospect of local surface plasmon induced fluorescence emission enhancement will be very bright.

Three-dimensional nonlinear ideal MHD equilibria with field-aligned incompressible and compressible flows

The equilibrium properties of three-dimensional ideal magnetohydrodynamics (MHD) are investigated. Incompressible and compressible flows are considered. The governing equations are taken in a steady state such that the magnetic field is parallel to the plasma flow. Equations of stationary equilibrium for both of incompressible and compressible MHD flows are derived and described in a mathematical mode. For incompressible MHD flows, Alfvénic and non-Alfvénic flows with constant and variable magnetofluid density are investigated. For Alfvénic incompressible flows, the general three-dimensional solutions are determined with the aid of two potential functions of the velocity field. For non-Alfvénic incompressible flows, the stationary equilibrium equations are reduced to two differential constraints on the potential functions, flow velocity, magnetofluid density, and the static pressure. Some examples which may be of some relevance to axisymmetric confinement systems are presented. For compressible MHD flows, equations of the stationary equilibrium are derived with the aid of a single potential function of the velocity field. The existence of three-dimensional solutions for these MHD flows is investigated. Several classes of three-dimensional exact solutions for several cases of nonlinear equilibrium equations are presented.

Increasing luminous efficiency of led by joint dimming mode with adjustable peak current

Luminous efficiency and color temperature of LED chip are affected by current and temperature. PWM dimming mode only works at two kinds of current levels-rated current and zero current. It has smaller effect on color temperature compared with linear dimming mode, but it will reduce the luminous efficiency of lamps. Linear dimming mode has higher luminous efficiency by comparison. The two dimming modes above cannot keep color temperature stable and Luminous efficiency high. Therefore, the paper designed a joint dimming mode by integrating advantages of the two modes. The dimming method not only adjusts peak current, but also changes the duty cycle of dimming signals. The injected average current is kept stable by reducing peak current and increasing the duty cycle. The decreased luminous efficiency by the raise of temperature was made up for. Then according to the mathematical model of total flux and current, the author calculates the mathematical mode of flux affected by temperature. It proves the fact that adjusting peak current slightly can compensates for the reduced luminous efficiency affected by temperature through theoretical calculation. In addition, the final peak current after calculation can contribute to the adjustment parameter of joint dimming modes.

MATHEMATICAL MORPHOLOGY APPLIED IN RECOGNITION OF HEART SIGNS

The paper proposes an improved, efficient and low-power approach of processing in the digital filtering using mathematical morphology multistage mode for the detection of QRS complex in the ECG signal.

MATHEMATICAL MORPHOLOGY APPLIED IN RECOGNITION OF HEART SIGNS

The paper proposes an improved, efficient and low-power approach of processing in the digital filtering using mathematical morphology multistage mode for the detection of QRS complex in the ECG signal.

The Model of the Korla Fragrant Pear Mature Based on Effective Accumulated Temperature

In order to investigate the mature law of Korla fragrant pear with mathematics method, Korla pears in Aksu area be taken as the study object, and the fruit hardness and soluble solid content (SSC) be selected as the research index. The data of the two indices in the mature process are analyzed with Excel, SigmaPlot and Matlab. To draw the change rule of indices and establish the mathematical mode. The research shows that the effective accumulated temperature reaching up 3000°C to 3843°C is main mature stage of the Korla fragrant pear, and there is an accelerating stage in which. The change rule can be precise description by the established mathematical model that can provide reference for fruit maturity modeling.

Generator Stator Bar-Ends Cure-Heating Monitor System on Fuzzy PID

The process of electric generator stator bar-ends cure-heating is a key step during the generator production. However, since the cure-heating system is a non-linear and one-step inertial system of great coupling. Because of the resistance wire (or wire rod body resistance), air convection, the temperature and other environmental factors, it is difficult to establish accurate mathematical mode. The traditional PID control system does not achieve the desired effect. On the one hand, its overshoot is so large that the tolerance can be up to 6, on the other hand, it is difficult to regain balance once the system is perturbed. The paper makes a thermal chemical analysis of the cure-heating system, then builds a thermodynamics model. To control the non-linear and one-step inertial system, it adopts the method of Fuzzy self-tuning PID parameters to adjust the PID parameters including, and the output according to the real-time heating temperature feedback, thus, controlling the heaters action to achieve the objective of heating temperature control and solving the strong-coupling between the multi-loops of heating and improve the automatic control degree of the cure-heating control system. By simulating in MATLAB and analyzing the simulated results comparing Fuzzy-PID control effects with traditional PID, the results show that the method of Fuzzy-PID control which is used to realize the real-time control of temperature in the stator bar-ends cure-heating system can exert strongpoint and avoid shortcoming of those two control methods. As it can not only exploit the advantages of Fuzzy control, such as strong Robinson Crusoe, fast response time, small overshoot, but also possesses the high quality dynamic tracking function and better static precision of PID control, it is a superior excitation temperature control scheme for stator bar-ends cure-heating system.

Synthetical Evaluation Model Based on Integer Programming for Arranging Single Round Robin Schedule

In this paper, the synthetical evaluation model based on integer programming for arrangement of single round robin schedule is established through analyzing the major factors of matches. Following, as an example, we analysis and evaluate the schedule of NBA 08-09 season according to this mathematical mode. All results are obtained with the MATLAB software.

Simulation Research on Effects of Low Velocity Characteristics to Direct Drive Volume Control Systems

The Direct Drive Volume Control (DDVC) Electro-hydraulic Servo System is a new Electro-hydraulic Servo System. It has the advantages of flexibility of AC servo motor control and high power of hydraulic servo system. Compared with the traditional electro-hydraulic servo system, the DDVC system is efficient, miniaturized integrated, convenient operated and economical. It has been used in many domains, and made great economic benefits. So it is widely considered to be one of the most important developing directions of the hydraulic control system. It will be widely used in more and more areas in the future. With the development of its application, how to improve the trajectory tracking precision of the DDVC system in low velocity motions becomes more important in the field. So that, the level of the low velocity characteristic impacted the system become to an important subject. In this paper, the mathematical mode of AC asynchronism motor Direct Torque Control was established, and the simulation mode was built. In addition, the idealized model of the DDVC system which based on united simulation of AMEsim/Simulink was established, simulation was executed. In order to make the research available, the low velocity characteristic of the DDVC system was also analyzed, and the low velocity characteristic simulation model was built. Computer simulation validated that the friction, the leakage and the mechanical losses are seriously influenced the system performance when the system working on the low velocity mode.

Research on the Low Velocity Accuracy Control of the Direct Drive Volume Control Electro-Hydraulic Servo System

The Direct Drive Volume Control (DDVC) Electro-hydraulic Servo System is a new Electro-hydraulic Servo System. With the development of its application, how to improve the trajectory tracking precision of the DDVC system in low velocity motions becomes more important in the field. So that, the level of the low velocity characteristic impacted the system become to an important subject. In this paper, the mathematical mode of AC asynchronism motor Direct Torque Control was established, and the simulation mode was built. In addition, the idealized model of the DDVC system which based on united simulation of AMEsim/Simulink was established, simulation was executed. In order to make the research available, the low velocity characteristic of the DDVC system was also analyzed, and the low velocity characteristic simulation model was built. Computer simulation validated that the friction is seriously influenced the system performance when the system working on the low velocity mode. An integral back stepping adaptive control law is designed to realize the friction compensation and load disturbance estimation. From the Lyapunov theory, the stability of the closed-loop system is proved. Simulation results show that LuGre friction in servo systems will lead to the effect of limit cycles and stick-slip. Moreover, the proposed compensation method can greatly reduce the effect and improve the system tacking accuracy and robustness.

Grinding Wheel Dynamic Balance Weight Type System Based on the Self-Optimal Fuzzy Control

.Grinding wheel as the research object in this paper and aim at the vibration signal use the weight balance principle to balance the centrifugal force caused by the eccentric whee. Designed a kind of self-optimization fuzzy controller, through online optimization correction factor realized the control rules of self-adjustment and self-improvement. Not only solved the problem of relying on the Precise mathematical mode as the conventional control system,but also make the control system has automatic adaptation for the changes of the object properties.Experimental results show that:the effect of the correct balance amount and the grinding wheel unbalance correction offset is good, the vibration drop rate reached 93.2%, has played a good role in inhibition of unbalance, the grinder vibration quantity significantly reduced and improved the performance of the control system.

Advance on conjunctive operation of surface water and groundwater

The implementation of conjunctive operation of surface water and groundwater is an efficient way to make good use of water resource, strengthen the management of groundwater resource, and solve the problem of water resource shortage in China. This research firstly summarizes the sort of conjunctive operation system of surface water and groundwater, and the principles to conduct conjunctive operation, introduces the mathematical mode category of conjunctive operation of surface water and groundwater, analyzes the present research situation of the optimal methods of it at home and aboard, makes clear the problems existing in this field, and then prospects the research tendency of this field. By the way, it puts forward an idea that the cross and fusion of hydrology, meteorology, ecology, soil science, and computer science will be the future research tendency of conjunctive operation of surface water and groundwater; so it supplies reference for further study of this field.

Vector Decoupling Control Strategy for Three-Phase Voltage Source PWM Rectifier

In view of the fact that active power and reactive power have coupling relation, a novel vector decoupling control strategy is presented for three-phase voltage source PWM rectifier. In the paper, the power control mathematical mode of the PWM rectifier is deduced based on the mathematical model of rectifier in synchronous d-q rotating coordinates, and a new voltage feed forward decoupling compensation control strategy is proposed. The simulation results show that the voltage and current of the three-phase PWM rectifier have better respond preference, the current aberrance is smaller and the voltage is steady under the control strategy. The PWM rectifier can implement PWM commute with unity power factor, but also feed back the energy to AC side with unity power factor.

A Multi-Objective Mathematical Model for Green Supply Chain Reorganization

This study considers a green supply chain design (GrSC) with environmental concerns. We develop a multi-objective mathematical mode for hub location allocation problem that captures the trade-off between our objectives. The first objective is related to the total cost: transportation & inventory cost and the second one is related to the environment impact, such as CO 2 emission. The strategic decisions considered in the proposed model define which warehouses should be selected as a distribution center (hub) and what transportation mode and organization which number of vehicles are required to move products in each period among suppliers, distribution center and warehouses. a new resolution process is proposed and meta-heuristic approach is applied to obtain Pareto frontier.

Research on Goal Programming Algorithm Based on Lingo

Goal programming is an important branch of operational research. In this paper, the theory of goal programming is detailed introduced including basic concepts, the mathematical mode. The basic ideas to solve goal programming are transforming goal programming into single-objective linear programming. An optimal solution is attained when all the goals are reached as close as possible to their aspiration level, while satisfying a set of constraints. Two solving methods-the simplex algorithm and the method of LINGO software t are discussed in the paper. Finally goal programming model are applied to the actual management decisions, multi-objective programming model are established and used Lingo software to achieve satisfied solution.

Analytical derivation and numerical experiments of degenerate scales for regular N-gon domains in two-dimensional Laplace problems

Degenerate scale of a regular N-gon domain is studied by using the boundary element method (BEM) and complex variables. Degenerate scale stems from either the non-uniqueness of BIE using the logarithmic kernel or the conformal radius of unit logarithmic capacity in the complex variables. Analytical formula and numerical results for the degenerate scale are obtained by using the conformal radius and boundary element program, respectively. Analytical formula of the degenerate scale contains the Gamma function for the Gamma contour which can be derived from the Schwarz–Christoffel mapping. Based on the dual BEM, the rank-deficiency (mathematical) mode due to the degenerate scale (mathematics) is imbedded in the left unitary vector for the influence matrices of weakly singular (U kernel) and strongly singular (T kernel) integral operators. On the other hand, we obtain the common right unitary vector corresponding to a rigid body mode (physics) in the influence matrices of strongly singular (T kernel) and hypersingular (M kernel) operators after using the singular value decomposition. To deal with the problem of non-unique solution, the constraint of boundary flux equilibrium instead of rigid body term, CHEEF and hypersingular BIE, is added to promote the rank of influence matrices to be full rank. Null field for the exterior domain and interior nonzero field are analytically derived and numerically verified for the normal scale while the interior null field and nonzero exterior field are obtained for the homogeneous Dirichlet problem in the case of the degenerate scale. It is found that the contour of nonzero exterior field for the degenerate scale using the BEM matches well with that of Schwarz–Christoffel transformation. Both analytical and numerical results agree well in the demonstrative examples of right triangle, square, regular 5-gon and regular 6-gon. It is straightforward to extend to general regular N-gon case.

Proposed Model for Optimizing Production System Using CMS

Manufacturing cells are created by grouping the parts that are produced into families. This is based on the operation required by the parts. These cells which consist of machine or workstation are then physically grouped together and dedicated to producing these part families. In this paper a mathematical mode is presented to grouping the machine parts and machine cell. The objective of the proposed model is to minimize the mean flow time and maximize the throughput. This work presents a Genetic Algorithm for the cell formation and part family.Here, the implementation procedure of GA in the CMS problem has been discussed along with the detail of algorithmic parameters used in the algorithm

The Research and Evaluation Study of Intensive Land Use of Industrial Park Based on RS and GIS Technology

It was a necessary request for current social economic development to establish an economical and environmental friendly society. Intensive land use was an important measure of establishing economical society and a critical way of balancing the relationship of economical construction, resources utilization and environmental protection and implementing scientific development concept. Since the development zones were the typical industrial concentration areas, the realization of intensive land use became extremely important. This article made basic investigation on land use, industrial development and economical situation for development zones, pushed data base establishment of land use management of development zones, evaluated intensive land use situation by GIS technology and mathematical mode and controlled existing problems of land use in development zones. Consequently, this article could offer basis for development zones auditing of expansion and updating, dynamic monitoring and policies making.

Application of the differential transformation method to vibration analysis of stepped beams with elastically constrained ends

The purpose of the present paper is to apply the differential transformation method (DTM) to deal with the vibration problem of stepped beams with general end supports and elastically constrained ends. The method demonstrates several advantages, such as rapid convergence, high accuracy, and computational stability. Unlike some approximate approaches which require correct assumed admissible function, the differential transformation method gives all natural frequencies and their mode shapes without any frequency missing. By using the DTM algorithms fully provided in this paper with general mathematical software packets, natural frequencies and mode shapes of these beams can be obtained easily for every boundary condition. Aspects such as boundary conditions, spring constant values, stepped beam types, step ratio and step location, which have a significant impact on frequencies and mode shapes, are taken into investigation in this paper.