gradient direction change 中文意思是什麼
gradient direction change
解釋
改變漸變發現-
To corner feature, both gradient magnitude change and direction change of gradient vector are discontinuity in a local image neighborhood, hence gradient - direction variation and gradient magnitude are used as another decision rule of the corner detection to improve antinoise
為了提高抗噪聲，根據角特徵不僅灰度變化是不連續的，且相對周圍其他點的梯度方向也是不連續的，提出利用梯度角變化和梯度幅值作為角特徵檢測的另一個準則。 -
In this application, the lorentz force generated by the interaction between the current in the wire and the geomagnetic field produces an electro - dynamic drag leading to a fast orbital decay. in this paper, we make an intensive study of the process of de - orbiting using electro - dynamic tether system. the concrete work includes : firstly, i have studied the basic principle of how to generate the electro - dynamic drag, modeled via accuracy geomagnetism, made a concrete analysis of the de - orbiting duration, the magnitude and direction of electro - dynamic drag under the action of the dipole and accurate geomagnetic models, set up a counterbalance between electro - dynamic torque and gravity gradient torque, emulate the de - orbiting process of spacecraft, and compared the change of six orbital factors and the de - orbiting duration under the action of the dipole and accurate geomagnetic models
本文對基於電動力纜繩的航天器離軌過程進行了深入研究，具體工作如下:首先，本文研究了電動力纜繩產生電動力拉力的基本原理，建立了精確地磁場模型;分別在偶極子模型和精確地磁場模型作用下，對電動力拉力的大小、方向、離軌時間及電動力纜繩傾角的大小進行了計算分析;建立了電動力力矩與纜繩系統重力梯度力矩的平衡關系;分析了電動力力矩為系統提供能量的原理;最後分別在偶極子地磁場模型和精確地磁場模型作用下，對受電動力纜繩作用的航天器的離軌過程進行模擬，分析了在不同精度地磁場模型下，航天器離軌過程中各軌道參數的變化情況，並比較了不同模型對離軌時間的影響。 -
The fem results indicated that as to the rough surfaces in sliding contact, the value of the contact pressure was very high which coursed a high value of the heat flow rate, meanwhile the sliding time was not enough for the frictional heat to transfer, thus the highest value of the body temperature occurred just on the sliding surfaces, which possessed a sharp thermal gradient in direction perpendicular to the sliding surface. so the great thermal stress was caused just by the sharp gradient and the thermal elastic distortion with which the contact pressure changed occurred simultaneously, thus this change of the contact pressure would affect the temperature distribution in return
對于相對滑動的粗糙表面，因實際接觸面積小而導致接觸壓力很大，這樣使得熱流密度會很大，同時由於滑動時間很短，熱來不及傳導，最高溫度發生在摩擦表面，在垂直於摩擦面的方向有很大的溫度梯度，使得熱應力很大，且最大應力發生在表面，同時產生熱彈性變形，這種變形使得接觸區域內的壓力分佈發生變化，這種變化又反過來影響了接觸區域的溫度分佈。 -
The method of bispectrum reconstruction detects fracture zones by learning the difference of frequency components because fracture can change the frequency components of seismic responses. the theory of time - frequency analysis computes the difference in the gradient direction of time - frequency spectrum
雙譜重構的方法就是根據裂縫會改變地震波頻率成分的基本想法，通過求取具有不同頻率成分的地震波的差異來實現對裂縫發育帶的檢測的。
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