Several non - linear phenomena are also analyzed . by using uncoupled thermal - structure analyzing method , with the consideration the additional stiffness caused by thermal stress , the finite element model for thermal - vibration analysis is obtained and two typical hypersonic wing structures are computed 運用非耦合熱-結構分析方法,考慮熱應力引起的附加剛度,得到熱環(huán)境下的結構分析的有限元模型,并計算了兩種典型結構的高超音速翼面熱結構。
In the second part , we try to apply orthogonal polynomial approximations to the dynamical response problem of the duffing equation with random parameters under harmonic excitations . we first reduce the random duffing system into its non - linear deterministic equivalent one . then , using numerical method , we study the elementary non - linear phenomena in the system , such as saddle - node bifurcation , symmetry break bifurcation , phenomena in the system , such as saddle - node bifurcation , symmetry break bifurcation , period - doubling bifurcation and chaos 本文第二部分嘗試將正交多項式逼近方法應用于隨機duffing系統(tǒng),提出與之等價的確定性非線性系統(tǒng)的新概念,并用數(shù)值方法對該系統(tǒng)在諧和激勵下的鞍結分叉、對稱破裂分叉、倍周期分叉、和混沌等各種基本非線性響應進行了初步探討。
An artificial neural network ( ann ) model was developed and used in different water bodies to predict timing for environmental changes as well as for the dynamics of resources . the results show that the ann model is superior to classical statistical models ( csm ) and can be used as predictive tool for highly non - linear phenomena 用人工神經(jīng)網(wǎng)絡方法對不同水域、不同環(huán)境因子之間非線性和不確定性的復雜關系進行學習訓練并預測檢驗,結果表明:人工神經(jīng)網(wǎng)絡方法在模擬和預測方面均優(yōu)于傳統(tǒng)的統(tǒng)計回歸模型,在資源與環(huán)境方面的應用是可行的,具有較強的模擬預測能力。