Sine-generated curves belong to a class of intrinsic functions which describe a curve by specifying its “direction angle”. The curve is determined by ω, the maximum angle which the curve makes with the horizontal, ...Sine-generated curves belong to a class of intrinsic functions which describe a curve by specifying its “direction angle”. The curve is determined by ω, the maximum angle which the curve makes with the horizontal, and the fact that the direction angle changes in a sinusoidal fashion along the path. Sine-generated curves are shown to be excellent approximations to the path of minimal average curvature, and expressions for radius of curvature and curve sinuosity are derived.展开更多
He jerks up,gasping for air,the back of his shirt soaked with cold sweat.Not again.He turns his head to the side,to his wife who lies sound asleep next to him.Even as an alumnus of Peking University,the top university...He jerks up,gasping for air,the back of his shirt soaked with cold sweat.Not again.He turns his head to the side,to his wife who lies sound asleep next to him.Even as an alumnus of Peking University,the top university in China,my forty six year-old father still suffers from nightmares about the Gaokao(also known as NCEE,or the National College Entrance Examination).Gaokao is the graduation exam administered to millions of high school seniors in China each year.While some students avoid this test by studying abroad,students who plan to attend universities in China have no choice but to prepare for the NCEE.Even though it is terribly grueling to study for and take the NCEE,most Chinese students see the test as their sole path to future success.展开更多
文摘Sine-generated curves belong to a class of intrinsic functions which describe a curve by specifying its “direction angle”. The curve is determined by ω, the maximum angle which the curve makes with the horizontal, and the fact that the direction angle changes in a sinusoidal fashion along the path. Sine-generated curves are shown to be excellent approximations to the path of minimal average curvature, and expressions for radius of curvature and curve sinuosity are derived.
文摘He jerks up,gasping for air,the back of his shirt soaked with cold sweat.Not again.He turns his head to the side,to his wife who lies sound asleep next to him.Even as an alumnus of Peking University,the top university in China,my forty six year-old father still suffers from nightmares about the Gaokao(also known as NCEE,or the National College Entrance Examination).Gaokao is the graduation exam administered to millions of high school seniors in China each year.While some students avoid this test by studying abroad,students who plan to attend universities in China have no choice but to prepare for the NCEE.Even though it is terribly grueling to study for and take the NCEE,most Chinese students see the test as their sole path to future success.
