In this paper, the author gives the formula of roots of a quadric equation over a field of2 k elements and presents the problem.

It overcomes the disadvantages of existing distortion calibration approaches. Assumed only with one order radial distortion, image coordinates of only 4 special collinear points are needed as well as the cross ratio of them.

该方法利用了透视投影中的交比不变性质，在畸变模型为一阶径向畸变的情况下，只需要空间共线的4个点的图像坐标和其交比，建立一元二次方程即可标定畸变参数。

New irrigation and undersoil heating systems were also installed at the same time as the 2003 work.

在2003年的那次大修中,新的灌溉系统和地热系统也被安装上了.

Many analysts consider below-average volume as a negative, because It'suggests a lack of eagerness.

许多分析师认为,交易量低于平均水平不是件好事, 因为这显示投资者缺乏买进的迫切愿望.

She is often angry at her son because his performance in school is always below average.

她儿子在学校的成绩一直很差,这总是让她非常生气.

Harry is below average in his lessons and Jim about up to average.

哈利的功课在中等以下,吉姆的功课刚达一般水平.

Children are banded as averageaverage and below average.

入学儿童按好、中、差三等编班.

It's obvious the products are below average quality.

很明显,这批产品地品质是中下水平.

The snowfall this month is below average.

该月的降雪量低于平均水平.

Their language development is below average.

他们的语言能力的发展低于一般水平.

The riders , aged 27 to 44, began with slightly below-average bone density.

这些年龄在27-44岁间的赛手, 比赛开始时的骨密度都稍微低于平均值.

Remember, half the people you know are below average.

永远记住: 你认识的人中定会有一半居于平均线以下.

These marks are well above / below average.

这些分数远在一般水平以上[以下].

The amount of snow this year has been below average.

今年的降雪量低于平均水平.

The brushes have bristles of animal hair, with a very fine point.

毛笔用动物的毛发制成, 笔尖很细.

This pen has a fine point.

这支笔的笔尖细.

She moved to the gardens from the hostel, moved from the dormitory area.

她从花园洋房搬到了宿舍, 又从宿舍搬到了小区.

They also cut his beard and hair before leaving the injured journalist in a suburban area.

在把这个受重伤的记者扔到郊区之前,他们还割掉了他的胡子和头发.

The suburban area of the capital near the Miyun Reservoir is a tourist resort.

密云水库地处京郊,是个旅游胜地.

The underground railway runs 24 hours a day, and there are-night cinemas, bars and restaurants.

地铁一天跑24小时, 还有通宵电影, 酒吧和旅馆.

The London Underground, also known as the Tube, is the oldest underground railway in the world.

地铁.你知道在英国俚语是地铁是怎么说的吗?