mathematical variable 中文意思是什麼

mathematical variable 解釋
數學變數
  • mathematical : adj 數學(上)的,數理的;嚴正的,精確的。 mathematical instruments 制圖儀器。 mathematical logic...
  • variable : adj 1 易變的,變化無常的,無定的 (opp constant steady)。2 可變的,能變的;變換的。3 【數學】變...
  1. Based on the general mathematical models of multibody system dynamics such as the kinematics models of multibody dynamical systems, the ordinary differential equation models and the differential algebraic equation models of dynamics, general forms of the sensitivity equations of the systems are deduced by using direct differentiation method and adjoint variable method

    基於通用的多體機械繫統運動學數學模型,常微分方程形式的動力學數學模型、微分/代數方程形式的動力學數學模型分別採用直接微分方法、伴隨變量方法推導出了系統的狀態靈敏度方程的通用形式。對于微分/代數形式的數學模型
  2. Mathematical expectation and variance of random variable with fuzzy probability

    模糊概率隨機變量的數學期望和方差
  3. The study has completed the design of two - phase inverter and made up of the two - phase inverter - motor system for experimental use it is a variable frequency adjustable speed system with a open - loop control of rotational speed, which consists of voltage - controlled oscillator circulating assign device inverter circuit and two - phase induction motor a accurate mathematical model is set based on the whole system, and simulator program of dynamic and steady condition is established, which is used to calculate the dynamic and steady performance by kron and symmetrical coordinate converter by simulator calculation and experimental research with specific parameter of the system, a comparison is made between predicted and experimental characteristics, experimental measurements are shown to compare closely with corresponding theoretical result it is compared with some variable frequency adjus table speed system comprising inverter and single - phase induction motor from the system efficiency torque pulsation and the effect of two - phase inverter capacitance based on the conclusion, harmonic cancellation pulse width modulation control of a two - phase inverter - fed induction - motor drive system is researched, which cancelled the low harmonic and improve the system performance

    通過對電機的kron變換和對稱分量變換,建立了系統較精確的數學模型,編制了系統動態及穩態運行的模擬計算程序分別計算系統的動態和穩態性能。通過對系統的具體參數進行了模擬運算和實驗研究,實驗和模擬結果進行比較,說明實驗和理論較為一致,並從系統效率、轉矩脈動及兩相逆變器電容的影響等方面與各種逆變器和單相異步電動機組成的變頻調速系統加以比較。在此基礎上,對兩相逆變器供電-異步電動機系統使用諧波抑制pwm控制進行了研究,由於減少了低次諧波,改善了系統性能。
  4. The general density function of sum of indepentent random variable of uniform distribution on [ 0, 1 ] is listed by enumerating a few special cases, where the mathematical inductive method is used

    摘要通過簡單枚舉一些特例,列出服從均勻分佈的多個獨立隨機變量和的密度函數一般公式,然後用數學歸納法進行嚴格的證明。
  5. This paper evaluates the underground water resources and its safe levels of miming, and then studies the availability of molepipe drainage, a kind of practical underground water regulation technique. starting with the elevation of underground water resources and a safe level of mining through variable system theory, this paper analyzes the conditions of underground water resources based on the well - studied determination method of determining the two hydrographical coefficients : rainfall infiltration replenishment rate and irrigation replenishment rate. then considering irrigation, rainfall, drainage and other related factors, a mathematical model is set up for the calculation of underground water storage, exploitation on water regulation

    論文從灌區的地下水資源及其可開采量評價分析方面入手,在對兩個主要的水文地質參數即降雨入滲補給系數、灌溉入滲補給系數確定方法研究的基礎上,對灌區的地下水資源狀況進行分析,依據灌區的灌溉、降雨、排水條件及各種現狀因素,建立了地下水資源量計算的數學模型,西安理工大學工程碩士專業學位論文計算得到青銅峽灌區地下水的最大補給量和可開采量;另外對在開發利用地下水資源過程中的地下水位的調控進行了初步的探討,在銀北灌區開展對暗管排水調控地下水位的試驗研究。
  6. There are five parts are as follows : in part one, the concept of switching function is introduced first to establish the nonlinear mathematical model of the induction motor variable frequency speed adjustment system which is fed by a sine pulse width modulated ( spwm ) inverter and takes the effect of the main magnetic circuit saturation into consideration, then the low frequency oscillation of the system is simulated according to the model. next, from the view point of energy conversion of the inverter - induction system, a criterion for the low frequency oscillation is proposed to determine whether the system is in low frequency oscillation which is judged by whether the interval of the negative current component of the inverter input current is more than 1 / fc ( fc is the carrier wave frequency of the inverter ) or not

    首先引入開關函數概念,建立了正弦脈寬調制( spwm )逆變器供電異步電動機,考慮主磁路飽和時的變頻調速系統整體數學模型,模擬系統的低頻振蕩;其次從逆變器-異步電動機系統能量轉換角度出發,提出通過檢測逆變器輸入電流中負電流的間隔時間是否大於1 / f _ c ( f _ c為逆變器載波頻率)來判定系統是否出現低頻振蕩;最後的實驗結果驗證了系統低頻振蕩建模和判據的實用性和正確性。
  7. From mathematical models for inverse scattering in two dimensional inho - mogenous media including variable impedance, all kinds of probable mixed variable impedance boundaries and cracks, from interior and exterior trans - mission problems and radiation condition, ill - posed integral equation and indicator function method are formulated for the diverse of boundary iden - tification. it is shown that the kernel of the integral equation characters the boundary of scatterer, which is determined by solving it by virtual of regularity method, meanwhile, some numerical tests are given. 3

    在二維非均勻介質逆散射邊界識別的數學模型(包括一般的非均勻介質,正交各向異性介質,變阻抗介質,各種可能的混合變阻抗邊界問題)下,由內透射問題和外透射問題以及輻射條件,推導了上述介質的邊界識別的積分方程和指示函數方法,由於積分方程的核充分表徵了散射物的邊界,由此說明只要利用正則化方法求解該積分方程,就可以確定散射物的邊界。
  8. The mathematical expression, which is used to calculate the variable phase center based on the mom, is derived first in the paper. it is proved that the variable phase center of the lpda is not superposition in the e - plane and the h - plane

    文中採用矩量法,首次導出了基於矩量法多分段計算可變相位中心的表達式,證明了偵測合一系統中常用的對數周期偶子天線( lpda )在e面和h面的可變相位中心不重合。
  9. For a class of shunt - wound active power line conditioner, based on analysis of mathematical model of system and target of control, the algorithm of fuzzy variable structure sliding mode control is presented. the control algorithm can avoid complicated calculation of harmonic electric current in traditional control algorithm, and realize the feedback control of electric current. the algorithm is simple and easily implemented

    針對一類並聯型有源電網調節器在分析系統數學模型和控制目標的基礎浙江大學博士學位論文上,提出了模糊滑模控制策略,避免了傳統控制方法中復雜的諧波電流計算,實現對電源電流的閉環控制,該演算法簡單、易於實現,模擬結果證實了變結構滑模控制的有效性。
  10. Abstract : this paper discussed two mathematical models for the problem of selecting an expansion plan over a planning horizon for an electric utility system. one of which is the model of optimal sequencing of power plants which is solved using lagrangian relaxation. another is the model of operation. the paper explicated concrete application of the lagrangian relaxation method in calculating block diagram for sloving the scheduling model and considered variable operating expense when calculating

    文摘:運用系統工程方法,建立了火電站興建次序優化模型及火電站運行方式模型,採用拉格朗日鬆弛法研究火電站興建次序的優化,並給出了火電站興建次序優化模型的拉朗日鬆弛法計算.在優化計算過程中考慮了可變運行費用問題
  11. About the large deformation description, a multi - floating coordinate system is adopted. it can effectively reduce the error of discretization. this paper deals with the design of restrained variable structure control in the way of phase plane analyse, which is concise and avoids complex mathematical descriptions. a new method is promoted for flexible spacecraft control by describing flexible spacecraft dynamics equations as t - s fuzzy model and designing a pdc fuzzy controller

    將撓性航天器姿態動力學方程描述為t - s模糊模型為撓性航天器控制提供了新思路;模擬結果表明,基於t - s模型的pdc模糊控制器能滿足撓性航天器大角度姿態機動的精度要求,並能有效抑制帆板振動,具有一定的智能性。
  12. A hydrodynamic optimal method to enhance the energy conversion coefficient of the vertical - axis variable - pitch turbine is presented in this paper based on the analysis of the existing mathematical models, on the computational methods for predicting the hydrodynamic performance of turbines and on the available experimental results. by applying mathematical optimal theory, a mathematical model for optimizing the hydrodynamic attack angle of the blades of turbines is formulated and some numerical results are obtained as well

    本文在總結和研究豎軸可調角直葉水輪機水動力性能計算的現有數學模型,計算方法和實驗結果的基礎上,運用最優化理論,給出了改善和提高該種水輪機能量利用率的一種優化方法,建立了數學模型,並得到了計算結果。
  13. The obtained results in the paper are as follows : ( 1 ) the expansion of fourier series of orthogonal trigonometric polynomial for conditional mathematical expectation and function of random variable ; ( 2 ) the best approximation of trigonometric polynomial about another random variable for function of a random variable ; ( 3 ) the best approximation order of trigonometric polynomial for function of random variable

    摘要獲得了如下結果: ( 1 )條件數學期望及隨機變量函數的三角多項式級數表達; ( 2 )一個隨機變量關于另一個隨機變量的三角多項式的最佳逼近; ( 3 )隨機變量函數被隨機變量三角多項式最佳逼近的階。
  14. Abstract : this article is based on the theory of fuzzy optimization design. the running speed and width and initialtensileforce and interval distance of roller are its design variable. the objective function is the minimum power loss of the traction motor. it constructs the fuzzy optimization mathematical model of the two - way running belt conveyer ' s main parameters

    文摘:以模糊優化設計理論為基礎,以雙運帶式輸送機輸送帶的運行速度、寬度、初張力及托輥間距為設計變量;以牽引電機運行的最小功率消耗為目標函數,構造出了雙運帶式輸送機主參數的模糊優化數學模型。
  15. With the consideration of the vertical wave effect of soil and soil - pile interaction, an approximate analytical solution to vertical vibration of pile system with variable impedance in visco - elastic layered soil is developed. a simplified and practical mathematical model for interaction between soil layers is proposed, and its applicability is theoretically investigated. based on this model and by using laplace transforms and the transmit property of impedance function, the analytical expression of the impedance function and solutions of the displacement and velocity response function in frequency domain and in time domain at the pile head are derived

    4 、從三維軸對稱土模型出發,對考慮樁土耦合作用、土層層間聯系以及樁周土豎向應力梯度變化條件下的成層粘彈性土中完整樁及變阻抗樁系統縱向振動問題進行了研究,提出了成層土中變阻抗樁系統縱向振動問題的近似解析解法和樁周土層層間相互作用的簡化而實用的數學模型,並利用拉氏變換和阻抗函數的傳遞性,獲得了成層土中任意段變阻抗樁樁頂阻抗函數的解析表達式,以及樁頂速度導納和時域速度響應解析解和半解析解。
  16. Taking core loss into account has important effect to improve the torque performance of the motors " field oriented control. in this paper, the transient mathematical model of the asynchronous motor with core loss is setup. the method is proposed that minimizes the loss in a variable speed and torque at the synchronous rotating coordinate

    在對損耗分析的基礎上,建立了考慮鐵損時異步電機的動態數學模型,推導出在同步旋轉坐標系下變速、變轉矩時使電機功率損耗最小的方法,並且結合矢量變換提出了基於快速轉子磁場定向的矢量控制。
  17. This paper studies an ac servo system with the permanent magnet synchronous motor ( pmsm ) as the executive component. the disadvantages of the conventional methods of ac servo system are demonstrated by computer simulation and by analyzing the mathematical models of the pmsm and the vector decoupling control strategy. then, an improved double - pi combined with variable structure servo controller is proposed

    通過對永磁同步電動機的數學模型和矢量解耦控制策略的理論分析,以及基於雙pi結合單p位置調節的伺服系統的模擬實驗,揭示出經典的伺服控制方法的缺陷,並提出了一種改進的雙pi結合變結構的三閉環調節的伺服控制器設計方案。
  18. Time domain noise is simulated by the mathematical pseudo uniform or normal random variable and coupled to deterministic signals such as rectangular ( rect ), triangular ( tria ), unit step exponential ( uexp ), even exponential ( eexp ), or gaussian ( gauss ) pulse voltages in finite number of time samples in finite time period

    用數學類真均勻或常態隨機變數模擬時域雜訊,與定然時域訊號如,方形、三角、指數遞減、或高斯等電壓脈波在有限時域?圍之有限個時域取樣結合。
  19. The physical and mathematical models are founded. numerical simulation of marangoni convection in the liquid bridge and gas channel was performed by employing the primitive variable method and using galerkin finite element method, which is applied for discretization of non - dimensional governing equations and boundary conditions. the relationship between the suppressing status of mc in the liquid bridge and the inlet gas velocity or the channel width is obtained, and the suppressing status of some kinds of marangoni numbers ( ma ) or size ratios of liquid bridge a is analyzed

    採用原始變量法,用galerkin有限單元法對無量綱控制方程及邊界條件進行離散后,數值模擬了微重力條件下半浮區硅熔體及氣體流道內的marangoni對流,得出了無量綱氣流沖刷速度及流道寬度變化和熔體內熱毛細對流抑製程度的關系,進而分析了不同的無量綱參數ma數和不同熔體幾何尺寸比a下熱毛細對流抑制情況。
  20. Then the mathematical problem of nonlinear heat diffusion with temperature dependent thermal conductivity has been derived during laser irradiation of two - layer structures. to solve this problem, a kirchhoff transformation and further time variable transformation has been used

    於是,文中還用有限容積法將溫度場定解問題離散化,選擇合適的空間網格和時間網格,通過matlab編程實現對四維溫度場的數值模擬。
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