Outline

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

Presented by:

Muhammad Aamir Cheema, Lecturer IT at James Cook University Australia, Sydney campus

Who Am I? A Student

BSc. Electrical Engineering UET Lahore (2001-2005)

Masters by research University of New South Wales (UNSW) Sydney (2005-2007)

Currently a PhD Student at UNSW Sydney Research Area: Databases

Who Am I? A Teacher

Tutor @ University of New South Wales, Sydney Lecturer IT @ James Cook University Sydney

Campus Courses Taught:

Database Systems Implementation Database Systems Operating Systems and Architectures E-Business Technologies Portable Programming C++

What is Research?

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: Numbers are not displayed on the screen

Version 2: 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:1. No element can be seen twice2. 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 Is 1 missing? Is 2 missing? Is 3 missing? . . .Algorithm: For each number i from 1 to n

Check whether i is missing or not

Performance: Space Usage: (n-1) elements O(n)

Running Time: O(n2)

Sorting: A faster solution

4,2,8,1,10,9,5,3,61,2,3,4,5,6,8,9,10

Sort the numbers Scan the list to find missing numberPerformance: Space Storage: O(n) Running Time: sorting time + final scan

nlogn + n O(nlogn)

Bucket: Even faster approach

4,2,8,1,10,9,5,3,6Algorithm: create an empty array of size n For each element i in the list

Mark the element at index [ i ]

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: Developed solution for Version 2 Performance: Space Usage: O(n) Running Time: O(n)Version 1:A solution is required that

1. Accesses each element only once Running Time: O(n)2. 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: Find the sum of 1 to n numbers S=n(n+1)/2 For each number i

S=S-i S is missing numberPerformance:

Space Usage: O(1)Running Time: O(n)

My Research

Nearest Neighbors Problem

Given a set of objects O, find k objects closest to any given query object

Objects are represented by their location coordinates

Applications: Find 5 taxis nearest to my current location Find 3 hotels closest to Islamabad Airport

A Brute Force Solution

Algorithm:

Let q be the query object For each object x

Find the distance of x from q Report the k objects with the minimum

distance from q

Problems with the brute force approach

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)???

To update the results, compute distance of all objects again

A better solution

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

CircularTrip1

Explore the objects around q in an iteratively increased circle Use grid based index (visit the cells around q that intersect the circle)

1- Muhammad Aamir Cheema, Yidong Yuan, Xuemin Lin, "CircularTrip: An Effective Algorithm for Continuous kNN Queries", DASFAA 2007, Thailand.

q

p1

p2

r

Updating the result on movement of objects

q

p2

p1

Incoming objects: any non-result object p entering inside the circle Insert p into answer list

Outgoing objects: any result object leaving the circle delete p from answer list

Hanlde all the object updates as mentioned above

Case 1: answer list contains k or more than k objects Keep k closest objects and discard other

Case 2: answer list contains less than k objects Same as initial computation except the

starting radius is distk

distk

Higher Studies Opportunities in Australia

Student Visa Apply in any institution you like Get admission letter Take IELTS exam (you need 6 band overall) Show bank statement

Permanent Visa Get three year work experience in Pakistan Take IELTS (minimum 7 band in each module) Apply for Permanent residence (PR) visa 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

Student Visa Quick (you will not need to wait to complete 3 yrs work

experience to get PR) You become eligible for PR once you complete your

degree (duration must be at least 2 years) in Australia

Permanent Visa Less expensive (once you are citizen your chances of

getting scholarship grow enormously)

When Australia?

Education in Australia is not cheap but Australia is accomodating

Prefer European countries or try HEC scholarships if you are not interested in settling abroad

Getting Jobs in IT industry

University degrees teach you little bit of everything

A regular student becomes “Jack of all trades but master of none”

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

www.cse.unsw.edu.au/~macheema Google search “Muhammad Aamir Cheema” macheema@cse.unsw.edu.au

THANKS