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Social Science PhDs Five+ Years Out

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  • dissertation - matière potentielle : chair figures
  • cours - matière potentielle : with the career goal
  • dissertation - matière potentielle : advisor
  • cours - matière potentielle : achievements
  • cours - matière potentielle : experiences from a national sample of phds
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February 29, 2008 University of Washington  Center for Innovation and Research in Graduate Education Graduate School/College of Education  Box 353600,  Seattle, WA  98195  Phone: 206‐616‐6794,  Fax: 206‐616‐6762  Careers  of Geography PhDs    Findings from Social Science  PhDs—Five+ Years Out  Victoria Babbit∗ Elizabeth Rudd  Emory Morrison  Joseph Picciano  Maresi Nerad  * Victoria Babbit is a doctoral candidate in  geography at the University of Washington, Seattle.   Her dissertation research examines Swedish  campaigns to combat human trafficking as they  relate to concerns about gender equality,  immigration, citizenship and EU integration.  She is  currently a guest researcher at Stockholm  University's Centre for Research in International  Migration and Ethnic Relations. 
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  • geography phds
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6.087 Lecture 1 – January 11, 2010

Introduction to C
Writing C Programs
Our First C Program
1 What is C?
Dennis Ritchie – AT&T Bell
Laboratories – 1972
16-bit DEC PDP-11
computer (right)
Widely used today
extends to newer system
architectures
efficiency/performance
low-level access
1 Features of C

C features:
• Few keywords
• Structures, unions – compound data types
• Pointers – memory, arrays
• External standard library – I/O, other facilities
• Compiles to native code
• Macro preprocessor
2 Versions of C

Evolved over the years:
• 1972 – C invented
• 1978 – The C Programming Language published; first
specification of language
• 1989 – C89 standard (known as ANSI C or Standard C)
• 1990 – ANSI C adopted by ISO, known as C90

• 1999 – C99 standard

• mostly backward-compatible
• not completely implemented in many compilers
• 2007 – work on new C standard C1X announced
In this course: ANSI/ISO C (C89/C90)
3 What is C used for?

Systems programming:
• OSes, like Linux
• microcontrollers: automobiles and airplanes
• embedded processors: phones, portable electronics, etc.
• DSP processors: digital audio and TV systems

• . . .

4 C vs. related languages

• More recent derivatives: C++, Objective C, C#
• Influenced: Java, Perl, Python (quite different)
• C lacks:
• exceptions
• range-checking
• garbage collection

• object-oriented programming

• polymorphism

• . . .

• Low-level language ⇒ faster code (usually)
5 Warning: low-level language!

Inherently unsafe:
• No range checking
• Limited type safety at compile time
• No type checking at runtime
Handle with care.
• Always run in a debugger like gdb (more later. . . )
• Never run as root
1
• Never test code on the Athena servers
1 Athena is MIT's UNIX-based computing environment. OCW does not provide access to it.
6 6.087 Lecture 1 – January 11, 2010

Introduction to C
Writing C Programs
Our First C Program
7 Editing C code

• .c extension
• Editable directly
• More later. . .
7 Compiling a program

•gcc (included with most Linux distributions): compiler
• .o extension
• omitted for common programs like gcc
8