Lesson 6

Create system model/process for design

Exercise 6 Abstraction & Modeling

Abstraction - conceptual perspective of problem and possible solutions by using models to represent different possible designs

Simulations - model to do things not in real life, do simulation first (like flight simulator, Matlab, simulink, etc.)

Model - purposeful representation

• Computerized simulation
• Abstract set of eqns describing relationship among variables
• Formats:
  • mathematical
  • symbolic
  • graphical
  • computer-based
    • SImulation
    • Finite element method
    • Computer-aided design
  • concrete model with stuff like play-doh, concrete

Types of models:

• Iconic model
• analogical model
• symbolic models

Architects use solid models (example hanging chain model, use mirror to see result

Symbolic - symbol on EAS - pendentive dome 1500-year old symbol of architectual advance

Sharding (database architecture) uses symbolic

Urban canyons street is flanked by buildings on both sides... GPS may not work very well bc affects temp, RF, etc.

Friis transformation equations ratio of rx to tx poewr

Fresnel zone and Radii for ray tracing and radio reception

Moore's Law number components per IC doubles per two years. Approaching single micron, will reach some sort of bottleneck

==> 3D design?

Metcalfe's Law - n nodes is proportional to n(n-1)/2 which proportional to n^2 asymptotically

So instead we have switch or router to establish connection - interactions between any person in the world

netoid function model facebook user growth 2004-2013, and fit his law

Metcalfe father of Ethernet

Reed's Law sum k=2 to n of n choose k = 2^n - n - 1

A set of n people has 2^n-n-1 possible subsets with at least two people

Erdos Pal

Hungarian mathematician lots of papers with lots of collaborators

Six degrees of separation how many people of separation

Dunbar's number

Humans can only maintain 150 stable relationships

If write paper with Professor Lu, Erdos number is 4

Infectious disease Daniel Bernoulli created mathematical model to defend the practice of inoculting against smallpox

P=(R^N - 1) / 2

P=327200000

R=3

S=4

import math

4*math.log(2*327200000+1, 3)

73.90861927965678 days for whole US to be infected without any measures taken

n^n > n! > 10^n for large n

successor, addition, multiplication, exponentiation, tetration, pentation, hexation

avogadro, skewes' number, steinhaus-moser notation, graham's number, TREE function, SSCG function

Hypertext and hyperlinks

Uberization - operating like Uber for a service

Occam's Razor - model should not be more complex than absolutely necessary, never include more than essential details

Shave away unnecessary assumptions or cutting apart two similar conclusions

Developing a model

Godel Escher Bach (GEB) 4-inch cubic redwood shows different letters in shadows, design by Douglas Hofstadter

An Eternal Golden Braid - has metaphorical fugue on minds and machines in spirit of Lewis Carroll (pen name)

Strange loop impossible drawings

Right hand paint left, impossible triangle, impossible stairs

I am a Strange Loop (2007) book about paradox .. AI quite popular

The Second Curve (new growth)

Yijing and Sigmoid function

S(x) = 1 / 1 + e^x

Functional graphs and charts (excel, etc)

CircuitLab - draw circuits (analog and digital design), in the cloud

Fritzing requires 8 euro donation... why

==> good if you already have it

Hardware Description Language (VHDL)

=> Model and language to describe it

Finite-State machine (FSM)

Example, turnstile

UML (Unified Modeling Language)

Similar to hardware description language, but allows to draw diagrams

Python package is PlantUML, can be done in the cloud

Mechanical engineering has Finite element method(FEM) or finite element analysis(FEA)

Low profile tire has damage, but also wheel

Chainless bicycles US20070228687A1, needs extremely strong metal because chainless

very easy to break, special design/material needed to make it happen

System and Process Models

System and Process models required

System model describes parts and functions that produce in expected (deterministic) or uncertain (stochastic) way

Process model (descriptive or prescriptive)

descriptive - flowchart

Model enhancement

Be able to explain to somebody not on design team

Why-why diagram, keep asking why

WSL, WSL2 on windows insider edition

Install particle, lets you use mobile app to control raspberry pi or program it

or just use command line interface

Node.js for server

Treasure your time