Result: Linear phase e simply a rigid shift in time, no distortion Nonlinear phase e distortion as well as shift DT

1. DTFT Properties and Examples 2. Duality in fs& ft 3. Magnitude/Phase of Transforms and Frequency Responses

Convolution Property 0(t)=h(t)*(t)←→Y(j)=H(ju)X( where h(t)←→H(ju) A consequence of the eigenfunction property

Fouriers derivation of the ct fourier transform x(t)-an aperiodic signal view it as the limit of a periodic signal as t→∞ For a periodic signal the harmonic components are spaced Oo=2π/ T apart. AsT→∞,Obo→>0, and harmonic components are space

Similarity of regulation between eukaryotes and prokaryote 1. Principles are the same: signals, activators and repressors, recruitment and allostery, cooperative binding 2. Expression of a gene can be regulated at the similar steps, and the initiation of transcription is the most pervasively regulated step

1Some examples of systems 2 System properties and examples CAusality

Can be continuous Trajectory of a space shuttle Mass density in a cross-section of a brain · Can be discrete dNa base sequence Digital image pixels Can be 1-D,2-D,·N-D For this course: Focus on a single(1-D) independent variable which we call“time

一、(15分)计算下列各题 1.已知x(t)