Lecture 5 case studies
1. Chemical inventory system
Chris was in charge of version 1 of MITs chemical inventory system, MITCIS. With higher
security required these days, MIT realized that its decentralized system of ordering,
Frangipani: A Scalable Distributed File System
Thekkath, Mann, Lee
Why not primary copy?
Actually they do use primary copy inside Petal
But many Petal primary/backup pairs in one FS
Work out our own design.
How to divide data among the network d
n-Channel MOSFET: Connecting with the npn MOSFET
A very similar behavior, and very similar uses.
iD ! K [vGS - V T(vBS)]2/2!
Final comments on
The Gradual Channel result ignoring and valid for v BS " 0, and v DS # 0 is:
iG (vGS ,v DS ,v BS ) = 0, iB (vGS ,v DS ,v BS ) = 0, and
iD (vGS ,v DS ,v BS ) =
[vGS " VT (v BS )]
K $vGS " VT (v BS ) " DS ' v DS
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
Department of Electrical Engineering and Computer Science
6.012 MICROELECTRONIC DEVICES AND CIRCUITS
Answers to Exam 1 - Spring 2008
Problem 1: Graded by Prof. Palacios
In the steady state the low level injectio
Right: Basic device
with vBC = 0
Below: One-dimensional structure for depletion approximation analysis*
Clif Fonstad, 10/15/09
* Note: We can't forget the n+ region is th
An n-channel MOSFET showing gradual channel axes
Extent into plane = W
Gradual Channel Approximation:
- A one-dimensional electrostatics problem in the x direction is solved to find
the channel charge,
6.824 2006: Scalable Lookup
Prior focus has been on traditional distributed systems
e.g. NFS, DSM/Hypervisor, Harp
Machine room: well maintained, centrally located.
Relatively stable population: can be known in entirety.
Focus on performance, semantics, r
I Part One
1. [10 points]: Why does Frangipani distinguish between read locks and write locks? Why is that
a better approach than having a single kind of lock?
The read locks allow multiple Frangipani servers to cache and use les and directories at the
Day 1 (Parallel Computing and OpenMP):
Fundamentals of Shared Memory Programming
Basic OpenMP concepts, PARALLEL directive
Data scoping rules
Basic OpenMP constructs/directives/calls
Parallelizing an existing code using OpenMP
Replication in the Harp File System
Liskov, Ghemawat, Gruber, Johnson, Shrira, Williams
2b+1 servers, keeps going w/ up to b failures, might recover from > b
improvements over viewstamped replication:
supports concurrent/overlapped op