弦線中點 的英文怎麼說
中文拼音 [xiánxiànzhōngdiǎn]
弦線中點
英文
center of chord-
The signal we named it fundamental wave ; according to the fundamental wave, coefficients of the fundamental wave can be lined in a sequence. when the unique of the dissolve of the fundamental wave can be confirmed, the sequence of the coefficients can be regarded as one of representation forms of the signal itself ; theory of dissolvable signal shows that when order of the matrix of fundamental wave sampling equals to number of fundamental waves, the sequence of the sampling values from sampling points must be matched one by one with the sequence of the coefficients of fundamental waves. the sampling composed by sequences of the sampling values must be full sampling ; the relevant deductions of the theory of dissolvable signal shows that when sampling the signal, sampling frequency must be lager than the ratio of the number of fundamental waves to the occupation time of the fundamental waves ; to band - limited signals, when the fundamental wave is a sine signal, the results from the relevant deductions of theory of dissolvable signal is coherent to the classic sampling theory
本文通過分析認為，當信號集中的任一信號可表示為一系列已知信號的線性代數和時，信號集便構成可分解信號集，已知信號稱為基波信號；對可分解信號而言，基波系數構成一序列，當對指定的基波信號集分解唯一確定時，系數序列本身便是信號的一個表示；可分解信號采樣定理指出當基波樣值矩陣的秩等於基波數時，則由采樣點處的采樣樣構成的樣值序列必與基波系數序列一一對應，從而由該樣值序列構成的采樣必為完全采樣；可分解信號采樣定理中的推論指出，對信號集進行采樣，采樣頻率必須大於其信號分解的基波數與其對應時長之比；對有限帶寬信號，若基波信號為正弦信號時，由可分解信號采樣定理推論給出的結論與經典采樣定理一致。This dissertation emphasizes on the creation of image space, the author present a display system in which screen moves with a sinusoidal velocity profile to create image space. this paper uses linear approximation to make the system display homogeneous graphic and analyzes worst - case positional error due to linear approximation
本論文重點分析了顯示單元中成像空間的構造，提出屏幕按正弦曲線運動的方式來構造成像空間，用線性近似的方法得到均勻的圖像，並分析了由於線性近似帶來的最大屏幕位置誤差。The main work of this paper was as fellows : ( 1 ) generalized the development of pre - stressed steel structure in our nation and abroad, and pointed out the main problem in practice ; ( 2 ) presented the mechanism of pre - stressed steel structure and revealed its applicable range ; ( 3 ) established the optimization design model for pre - stressed steel structure, which accounts for constraints on stresses and displacements of structure ; ( 4 ) brought forward the optimization design method, which combined linear programming and the principle of full restriction, through which we can obtain the magnitude of each time pre - stress and the optimized sections of each members of structure ; ( 5 ) analyzed the best times of pre - stress and pointed out that 2 ~ 3 times is preferable ; ( 6 ) conducted optimization design on large - space steel roof, horizontal parallel steel truss with local cables, horizontal parallel steel truss with global cable, and ultra - static steel truss, the result of which indicated that the multiple pre - stress structure is very economic ; ( 7 ) compared different schemes of cable placement for horizontal parallel steel truss, and the results showed that the local cable only unloaded the second girders, but had no response on the first girders and stomach poles, while global cable could unload the second girders and the stomach poles outside of turning point of cable, thus proving that global cable is more economic than local - cable
本文的主要工作是：對國內外預應力鋼結構的發展歷史及現狀作了綜述和總結，指出當前預應力鋼結構工程實踐中存在的主要問題；闡述了預應力鋼結構的受力機理，並指出預應力鋼結構的適用范圍和特點；在考慮結構應力和變位約束的條件下，建立預應力鋼結構優化設計模型；提出多次預應力鋼結構優化設計方法和步驟，採用線性規劃和滿約束準則相結合的優化方法，可優化設計出施加的每一級預應力的大小，並得到結構各部分的優化截面；對多次預應力最佳的施加次數作了分析，並建議以2 3次為宜；為驗證文中理論和方法，分別對大跨多次預應力鋼屋架、局部布索的水平平行弦鋼桁架、整體布索的水平平行弦鋼桁架和局部布索的超靜定鋼桁架等算例進行了優化設計，經濟效益明顯；對水平平行弦鋼桁架的幾種施加預應力的方案進行比較，對于局部布索，預應力只對下弦起到卸載作用，對上弦和腹桿基本不起作用；而整體布索預應力除對下弦卸載外，對索折點以外部分腹桿也起到卸載作用，經濟效益好於局部布索。This paper develops iterative formula of sine and cosine function in document [ 40 ], and presents new pixel - level algorithms for generating archimedes and involute curves which are widely used in engineering
本文推廣了文獻[ 40 ]中正弦、餘弦函數的遞推公式，對工程繪圖中常用的阿基米德曲線和漸開線設計了新的逐點生成演算法。This paper expatiated that the mathematics models of ac motor is higher order, non - linear and closed coupling, multivariable input - output system. and introduces the principle and the algorithm of sine pulse width modulation ( spwm ), opened - loop space voltage pulse width modulation control ( svpwm ) and field oriented control ( foc ). finally, realized the control strategies of variable - frequency speed regulating using assembly and c language
文中闡述了交流異步電機的數學模型是高階、非線性、強耦合的多變量輸入輸出系統，介紹了交流電機的正弦脈寬調制、開環電壓空間矢量的u / f控制和磁場定向控制的原理及控制演算法，並利用dsp構成控制系統，通過匯編語言和16位定點c語言混合編程的方法實現了上述的變頻調速控制策略。Secondly, the problem of the curve - surface mutual transforming and smooth - finishing have been analyzed farther. for the surface intersecting problem : owing to the introduction of the boundary points, as long as the intersecting points on a certain line, the full intersecting line can be gained. the intersecting line either intersects at the boundary of the triangle surface or forms the loop ; during the course of tracking, the selecting of the pace is restricted by the curvature, the number of the gained intersecting points are not in proportion as the chord - length ; the intersecting points not only record the coordinate and store the parameter
對兩曲面求交問題，當曲面細化足夠小時，曲面求交可近似看成曲面與平面相交問題，引進了邊界點的概念，因此只要知道交線上的任意點，就可以將跨越許多曲面片的整條交線計算出來，所求出的交線或者跨越曲面的邊界，或者形成交線環；從初始點出發跟蹤求解整條交線的過程中，步長的選擇採用了通過曲面片曲率來約束的方法，用該方法求出的交點在不同曲面片上的分佈數目不與弦長成正比；該求交方法包含了各曲面片的邊界線與交線的交點的求解，可獲得邊界交點的坐標值及其參數值。分享友人