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l   Who am I?
l   What is research?
l   My Research
l   Higher studies opportunities in Australia
l   Getting jobs in IT industry

Presented by:
  Muhammad Aamir Cheema, Lecturer IT at James
  Cook University Australia, Sydney campus
Who Am I? A Student
l   BSc. Electrical Engineering UET Lahore
    (2001-2005)
l   Masters by research University of New South
    Wales (UNSW) Sydney (2005-2007)
l   Currently a PhD Student at UNSW Sydney
l   Research Area: Databases
Who Am I? A Teacher
l   Tutor @ University of New South Wales, Sydney
l   Lecturer IT @ James Cook University Sydney
    Campus
l   Courses Taught:
    l   Database Systems Implementation
    l   Database Systems
    l   Operating Systems and Architectures
    l   E-Business Technologies
    l   Portable Programming
    l   C++
What is Research?
l   Formally “a form of systematic enquiry that
    contributes to knowledge.”

Is research boring and difficult???
      NOT AT ALL if you like solving puzzles

Informally,
 Research ≈ Solving Puzzles
Let’s Play a Game1
Task: Find the missing number
 Given: Data set consists of numbers from 1 to 20

 Version 1:
   l Numbers are not displayed on the screen


 Version 2:
   l Find the missing number from the list below


             4,2,8,18,1,20,17,9,16,15,13,3,12,19,6,5,14,7,10

 Version 1 is more difficult because:
   l No element can be seen twice
   l We cannot memorize all the numbers


    1- Data Streams: Algorithms and Applications, S. Muthukrishnan
Brute Force Solution for
Version 2
            4,2,8,1,10,9,5,3,6
 l Is 1 missing?
 l Is 2 missing?
 l Is 3 missing? . . .
 Algorithm:
 l For each number i from 1 to n
   l Check whether i is missing or not

Performance:
  Space Usage:        (n-1) elements è O(n)
  Running Time:       O(n2)
Sorting: A faster solution
            4,2,8,1,10,9,5,3,6
            1,2,3,4,5,6,8,9,10
l Sort the numbers
l Scan the list to find missing number
Performance:
 Space Storage: O(n)
 Running Time: sorting time + final scan
                        nlogn +     n    è   O(nlogn)
Bucket: Even faster approach

                  4,2,8,1,10,9,5,3,6
Algorithm:
l create an empty array of size n

l For each element i in the list
    l   Mark the element at index [ i ]
l Unmarked index is the missing number
Performance:
  Space Requirement: O(n)
  Running Time:         O(n)
Solution for Version 1???
What we have done so far:
l   Developed solution for Version 2
l   Performance: Space Usage: O(n)
                     Running Time: O(n)
Version 1:
A solution is required that
    l   Accesses each element only once Running Time: O(n)
    l   Memorizes only one number       Space Usage: O(1)

    An example application: data passing through a network node
       (e.g; a router cannot store all the data passing through it
       and can see each element only once)
Hint
Given: numbers are from 1 to 10
Task: Nine numbers from the data are sent to
  user one by one, find the missing number

Sum of the numbers from 1 to 10 is 55
Solution
Given: Numbers are from 1 to n

Algorithm:
l Find the sum of 1 to n numbersè S=n(n+1)/2
l For each number i
    l   S=S-i
l S is missing number
Performance:
  Space Usage: O(1)
  Running Time: O(n)
My Research
l Nearest Neighbors Problem
Given a set of objects O, find k objects closest
  to any given query object
l Objects are represented by their location
  coordinates
Applications:
    l   Find 5 taxis nearest to my current location
    l   Find 3 hotels closest to Islamabad Airport
A Brute Force Solution
Algorithm:
Let q be the query object
l For each object x
    l   Find the distance of x from q
l   Report the k objects with the minimum
    distance from q
Problems with the brute force
approach
l   Distance of all objects from the query object
    is to be calculated Running Time = O(n)

What if all the objects are moving (e.g cars on a
  road)???
l To update the results, compute distance of all
  objects again
A better solution
l   Compute the distance of only the objects in
    vicinity of the query object q



    How to find the objects that lie in vicinity of q?

Use some spatial Index. i.e; grid index
                           1
CircularTrip
l   Explore the objects around q in an iteratively increased circle
l   Use grid based index (visit the cells around q that intersect the
    circle)



                                             p1


                                 r   q


                               p2


1- Muhammad Aamir Cheema, Yidong Yuan, Xuemin Lin, "CircularTrip: An
Effective Algorithm for Continuous kNN Queries", DASFAA 2007, Thailand.
    Updating the result on movement of objects


l   Incoming objects: any non-result object p
    entering inside the circle
    l    Insert p into answer list
l   Outgoing objects: any result object leaving the
    circle
    l    delete p from answer list
l   Hanlde all the object updates as mentioned
    above
l   Case 1: answer list contains k or more than k
    objects                                                         p
    l    Keep k closest objects and discard other
                                                                    1
l   Case 2: answer list contains less than k objects
    l    Same as initial computation except the
         starting radius is distk
                                                               q
                                                            distk
                                                       p2
Higher Studies Opportunities
in Australia
1.   Student Visa
     1.    Apply in any institution you like
     2.    Get admission letter
     3.    Take IELTS exam (you need 6 band overall)
     4.    Show bank statement
2.        Permanent Visa
     1.    Get three year work experience in Pakistan
     2.    Take IELTS (minimum 7 band in each module)
     3.    Apply for Permanent residence (PR) visa
     4.    Go there and get education with benefits of being a citizen
           of Australia (e.g; more scholarship opportunities, HEC
           loan etc)
Higher studies opportunities in
Australia
l   Student Visa
     l   Quick (you will not need to wait to complete 3 yrs work
         experience to get PR)
     l   You become eligible for PR once you complete your
         degree (duration must be at least 2 years) in Australia
l   Permanent Visa
     l   Less expensive (once you are citizen your chances of
         getting scholarship grow enormously)
When Australia?
l   Education in Australia is not cheap but
    Australia is accomodating
l   Prefer European countries or try HEC
    scholarships if you are not interested in
    settling abroad
Getting Jobs in IT industry
l University degrees teach you little bit of
  everything
l A regular student becomes “Jack of all trades
  but master of none”
l To get good jobs, you must become “Jack of all
  trades AND master of ONE”
Moral: Be master in at least on skill. e.g; JAVA,
  C++, networking, web development etc.

Try to learn something about everything and everything about something
Contact Information
l   www.cse.unsw.edu.au/~macheema
l   Google search “Muhammad Aamir Cheema”
l   macheema@cse.unsw.edu.au




              THANKS

				
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posted:10/9/2013
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