計算不穩定性 的英文怎麼說
中文拼音 [jìsuànbùwěndìngxìng]
計算不穩定性
英文
computational instability- 計 : Ⅰ動詞1 (計算) count; compute; calculate; number 2 (設想; 打算) plan; plot Ⅱ名詞1 (測量或計算...
- 算 : Ⅰ動詞1 (計算數目) calculate; reckon; compute; figure 2 (計算進去) include; count 3 (謀劃;計...
- 不 : 名詞[書面語] (剁物所用的木墩) a block of wood
- 穩 : 形容詞1 (穩定; 穩當) steady; stable; firm 2 (穩重) steady; staid; sedate 3 (穩妥) sure; rel...
- 定 : Ⅰ形容詞1 (平靜; 穩定) calm; stable 2 (已經確定的; 不改變的) fixed; settled; established Ⅱ動詞...
- 性 : Ⅰ名詞1 (性格) nature; character; disposition 2 (性能; 性質) property; quality 3 (性別) sex ...
- 計算 : 1 (求得未知數) count; compute; calculate; reckon; enumerate 2 (考慮; 籌劃) consideration; pla...
- 穩定性 : antiwhip
- 穩定 : 1 (使穩定) stabilize; steady 2 (穩固安定) stable; steady 3 (物質的性能不易改變的作用) stabi...
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Secondly, nonlinear threshold of two - dimensional rt instability was analyzed in planar and cylindrical and spherical geometries. density amplitude was defined relating to instable interface and formulae of nonlinear threshold values for rt instability in three geometries were given, then the lared - s code was used to simulate two - dimensional rt instability in three geometries and simulation results agreed well with the formulae
其次,討論了二維平面、柱和球幾何中rt不穩定性發生非線性偏離的閾值問題,給出了三種幾何中密度擾動振幅的非線性閉值公式,並且用lared一s程序進行了檢驗,計算結果表明柱和球幾何中的模藕合機制與平面幾何不同,存在幾何效應的影響。The software frontier in existence is a code built by j. glimm and his colleagues according to this method, and it can calculate the interface instability problems with simple interface
現有的frontier軟體包是基於界面追蹤方法編寫的,可以完成界面不穩定性問題在簡單界面情況下的計算。First, this paper gives an introduction of some methods of unequal probability sampling, their estimators and variance estimators, including sampling with pps with replacement, methods of sampling without replacement suggested by brewer, durbin, sampford, des raj, murthy, rao - hartley - cochran. then, at the basis of rao and bayless ' s study, we consider that population can be splited two random subpopulations, which are respectively drawn from different infinite super - populations, and compare the stabilities of estimators of the methods that given above. we find that the minor difference between two super - populations has great effect on the efficiency of the estimators for the population with moderately large coefficient of variation ( c. v. )
本文首先從理論上介紹了若干種不等概率抽樣方法,它們的估計量、估計量的方差及其估計,其中包括有放回ppz及pps抽樣,不放回不等概率抽樣中的brewer 、 durbin 、 sampford 、 desraj , murthy 、 rao - hartley - cochran等人的方法;其次,在rao和bayless兩人就樣本單元數n = 2的情形對上述抽樣方法進行比較的基礎上,將總體隨機地分成兩個子總體,視每個子總體取自不同的線性超總體,在文中,我們利用計算機實現隨機分組,並通過畫圖比較各方法估計量的穩定性,結果表明,對變異系數c . v . ( x )較大的總體而言,兩個超總體之間的微小差異將對估計量的穩定性產生很大的影響,從而說明rao和bayless的比較結果還不夠完善。High resolution eulerian adaptive algorithmfor interfaces instability
界面不穩定性的自適應歐拉數值計算In the light of all kinds of structural faces and their assembles along tunnel, the place and growth depth of instable cuneiform body in tunnel wall rock could be predicted, then its volume and weight of instable cuneiform body are estimated based on the equator plane projecting method and the solid body ratio geometry method, which offers reliable geologic data for designing corresponding supporting measure
摘要利用赤平投影法和實體比例幾何法分析隧洞圍巖穩定性,根據隧洞沿線所遇結構面相互組合形式,預測隧洞圍巖不穩定楔形體的位置及其發育深度,從而估算不穩定楔形巖塊的體積和重量,為設計相應的支護措施提供可靠的地質依據。Secondly, the paper shows the results from a great number of experiments of the weight algorithm that chooses samples by probability. the experiments point out that weight algorithm has a better generalization ability than the no weight algorithm. but a single weight algorithm is unstable and it needs tremendous time of calculation to combine many single algorithms into a stable one
其次對按概率取樣本的有權值演算法進行了大量實驗,實驗結果顯示出按概率選擇樣本權值演算法比無權值演算法的總體性能更為優秀,但其個體演算法的不穩定性以及為了獲得穩定結果所需要的巨大計算時間使其不可能成為一種能廣泛應用的演算法。Abstract : a continuity wave model is put forward for the dispersion processof liquid - liquid two - phase system, by coupling mass and momentum conservation equations of two - fluid model. the conditions that result in a dispersion choke and the weak instability of a dispersion process are derived from the model. the phenomena of catastrophic inversion and transitional inversion are explained. the effect of drop size distribution on the maximum volume concentration of a emulsion is predicted using the model. according to the theory herein, emulsion inversion is the regime transition of liquid - liquid system due to the instablity of a dispersion process. the effect of drop size distribution on the maximum volume concentration of a liquid - liquid emulsion only occurs in a certain range of weber numbers
文摘:以雙流體模型為基礎,通過質量守恆方程和動量守恆方程的耦合,提出了液-液兩相系中彌散傳質的連續波模型.由該模型得到彌散傳質過程阻塞和彌散傳質過程弱不穩定性產生的條件,計算了液滴尺寸及其分佈對乳化液極大堆砌分數的影響,解釋了劇變型乳化逆變和漸變型乳化逆變現象.研究結果表明,乳化逆變是由於彌散傳質過程的不穩定性而引起的懸浮體型態的改變,隨液滴尺寸多分散性的增大,極大堆砌分數增大;隨液滴平均尺寸的增大,多分散性對極大堆砌分數的影響減弱;當韋伯數足夠大時,液滴尺寸及其分佈對乳化液極大堆砌分數無影響The water quality respond relation of input - output measurements are established by systematic theory in this paper. according to the peculiarity of hydrology and the necessity of water quality inverse problem the multi - parameter inverse problem model based on ordinary differential equation is developed. the existence and uniqueness of the solution of the ordinary differential equation about two parameters or multi - parameter are to be proved. the unstability depending on errors between monitoring data and interpolation approximate data are analyzed and demonstrated. cubic spline interpolation function, the least two multiply and positive rule method are conjoined for obtained solution of multi - parameter. the results from this algorithm indicats its efficient to the multi - parameter identification in water quality modeling
本文應用系統理論,建立了水質多參數輸入輸出之間的響應關系;根據河流水文水質變化特點和參數反問題的需求,建立了水質常微分方程多參數反問題模型.根據常微分方程參數反問題的數學理論,作者給出了兩參數和多參數水質常微分方程反問題的解的存在性、唯一性的理論證明過程和結論;還針對水質現有監測資料的測驗誤差和插值近似計算誤差造成參數反問題的不穩定性,將三次樣條插值函數、超定方程最小二乘法和正則化演算法有機地結合使用,成功地給出了水質參數反問題的穩定化演算法.最後給出了應用計算結果Scramjet ignition technology and work on cooling the internal walls of a scramjet are also being assessed, the chinese say. computer modeling of scramjet combustion instability is also being modeled
該中國人透露,超燃沖壓發動機點火技術和冷卻超燃沖壓發動機內壁的工作也在評估之中。超燃沖壓發動機燃燒不穩定性的計算機模型也正在構建之中。In the model, johnson - cook strength is combined with gurson - tvergaard - needleman yield criteria, and random distribution of microvoids is used. results show that quasi - periodic axial fracture will appear, which obstructs the mirror current of the armature
在給定微孔洞的初始擾動時,計算結果解釋了鋁電樞表面將要形成的不穩定性,它導致了電樞外表面出現周期性的軸向裂紋,阻礙了鏡像電流,使fcg損耗增加。Abstract : the stability of the nonlinear comput ation is important in numerical weather prediction. in this paper, the concept, phe n omena and mechanism of nonlinear computational instability of the nonlinear evol ution equations in numerical weather prediction are discussed. an effective schem e, the square conservation shceme, is presented
文摘:簡述了數值天氣預報問題中非線性發展方程的非線性計算不穩定性的含義、數值計算現象以及計算不穩定產生的機理,給出了克服非線性計算不穩定的一個有效方法? ?平方守恆格式。This filter is a combination of adaptive ud decomposition kalman filter with quad method. it use quad method to detect and correct the gross errors in observations, use ud decomposition technique to improve computation precision and overcome the instability of filter caused by instability of values, when divergence of kalman filter had been detected, an adaptive filter is employed to adjust the prediction error covariance matrix
該法用擬準檢定法準確地探測和修正量測方程中存在的粗差;用ud分解演算法改進了計算精度,克服了由於數值不穩定帶來濾波的不穩定性;當判斷濾波器發散后,則啟用sage自適應濾波器,調整預測誤差方差,以克服濾波器的發散。The two - dimensional axisymmetric subsonic - transonic - supersonic flow in an experimental arcjet thruster is simulated numerically using flux vector splitting method. the profiles of density, velocity, temperature, pressure and mach number can be obtained by the computation. the computation grid and some computed results are given here. the test equipment such as power supply system, ignition system, propellant supply system, arcjet thruster, thrust measuring device and vacuum system are introduced briefly. some working phenomena of the arcjet are observed and discussed. three different kinds of instability appeared in the process of the experiments. except some important parameters are measured, it is found that the operating stability of argon is better than that of nitrogen
對一實驗電弧加熱式發動機二維軸對稱亞跨超音速流動進行了數值模擬,所採用的方法是矢通量分裂演算法.通過計算可以得出密度、速度、溫度、壓力和馬赫數的分佈.給出了計算所使用的網格和一些計算結果.簡要介紹了實驗所使用的設備,如電源系統、點火系統、推進劑供給系統、電弧加熱式發動機、推力測量裝置和真空系統.對所觀察到的一些工作現象進行了討論.有三種不同的不穩定性出現于實驗過程.除了所測量的一些重要參數,通過實驗發現氬比氮工作更穩定Problems of nonlinear computational instability in evolution equations
發展方程的非線性計算不穩定問題Numerical results are consistent with that of sandia laboratory experiment and agree with that of cth code too. an adaptive mesh refinement under 2d euler structure grid for multi - fluid flow is developed for resolving richtmyer - meshkov, rayleigh - taylor and helmholtz multi - fluid instabilities, and the high resolution interface properties can be obtained
數值模擬多介質流體richtmyer - meshkov , rayleigh - taylor , helmholtz界面不穩定性,用levelset函數定義euler坐標系中界面附近網格自適應判據,使得網格剖分更加合理,既能提高計算精度又能節省計算時間。In this paper, after studying the interface instability problems with complicated interfaces and the front tracking method, we rewrite the i / o files and initialization part of frontier code and append many new functions and variables in this code. the new code version can be applied successfully to complicated interface problems, which set up a good foundation to farther developments
本文在對復雜界面的界面不穩定性問題進行研究分析的基礎之上,通過改寫該軟體的初始化和輸入、輸出部分,並加入了大量新的函數和變量,成功實現了界面形狀的改變和改形后的相應計算,彌補了軟體現有的不足,為其適應實際工程應用要求奠定了基礎。Aiming at solving the shocking problem during the processes of starting and stopping of the traveling hydraulic system, the paper has set up a the ramping function of the minimum ramping time. it combines the fuzzy - adjustable - pid control strategy and the dead - domain control strategy to solves no - stable problem when paver works at low speed
針對攤鋪機起步、停車的沖擊問題,提出了最短斜坡函數的設計方法;針對攤鋪機低速不穩定性問題,分別採用帶死區的pid和模糊自適應pid演算法相結合的方法進行控制。Furthermore, numerical algorithms used to solve the linear system are introduced. next, after briefly discussing several causes of the late - time instability of the tdie solvers, a novel viewpoint about the instability is proposed. the marching - on - in - time algorithm ( mot ) is described and some temporal bases are discussed
其次,在簡要分析了引起時域積分方程( tdie )時間步進演算法求解的后時不穩定性問題的幾個原因后,指出引起時域積分方程時間步進演算法的后時不穩定性的主要原因是離散tdie時採用了不精確的數值計算方法和不恰當的近似。Firstly, two - dimensional rt instability in cylindrical geometry was simulated by the lared - s code and the results agreed well with the linear theory of rt instability in cylindrical geometry
首先,利用lared - s程序模擬二維柱幾何中rt不穩定性的增長,計算結果與線性理論符合得很好,檢驗了程序的可靠性。On the basis of producing the mathematical model of calculating the induced currents on the passive feedback coils, the distribution and variation of the induced currents and the eddy currents magnetic field are given by numerical calculation. these conclusions are necessary to study the vertical unstability of plasma and design the coils
在建立求解被動導電板感應電流數學模型的基礎上,通過數值計算,給出了感應電流的分佈和變化情況,同時對渦流磁場的分佈和變化也給出詳細的計算結果,這些結論對研究等離子體垂直不穩定性和線圈的設計是必需的。分享友人