Chapter 3 Technology of Electronic Commerce 3.1 A short history of the Internet and the web The Internet was the result of some visionary thinking by people in the early 1960s who saw great potential value in allowing computers to share information on research and development in scientific and military fields. J CR Licklider of MIT, first proposed a global network of computers in 1962, and moved over to the Defense Advanced Research Projects Agency(DARPA) in late 1962 to head the work to develop it Leonard Kleinrock of MIT and later UCLA developed

Chapter 2 The strategy of the development of E-Commerce 2. 1 The importance of the development of E-Commerce's research The impact of e-commerce, particularly in business to business(B2B)transactions, continues to grow. Customers increasingly expect to be able to deal with suppliers electronically as a matter

Bounded gain There exist very easy ways of testing(analytically) whether S Gu)< SISO Bounded Gain Theorem: Gain of generic stable system

In going from the state space model i(t)=A.(t)+ Bu(t y(t)= Ca(t)+ Du(t) to the transfer function G(s)=C(sI -A)-B+D need to form the inverse of the matrix(sI- A)-a symbolic inverse- not easy at all For simple cases, we can use the following

properties of finite dement soltions Noded point equilibrio At a node, the sow of he elemeat nodal forces s in equilibriun with Hhe externed loads

Why is the element stiffness matrix singular in a finite element formulation? 1. So that it can accomodate rigid element dis- placements without introducing spurious nodal 2 Because we made a mistake in the formula- tion the stiffness matrix should not be sin- g 3. Because we havent enforced any displace ment boundary conditions(it's a variational approach after all) Statement(1)

Unit #10- Principle of minimum potential energy and Castigliano's First Theorem Principle of minimum potential energy The principle of virtual displacements applies regardless of the constitutive law. Restrict attention to elastic materials(possibly nonlinear). Start from the Pvd

5. 19 Reaction between Dislocation Condition 1. Geometrical condition

1概 2S0炉气的制造 3炉气的净化与干燥 4二氧化硫的催化氧化 5三氧化硫的吸收 6用其它含硫原料制硫酸 7三废处理

6. 8 Diffusion Mechani sm Flick's' law in microscopic form 1. One dimensional diffusion. jump frequency period probability of atom jumping to nearest position