Rank: 41 based on 1150 downloads (last 30 days) and 47 files submitted
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Michael Chan

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Personal Profile:

I was a Security Specialist for software security and cryptology [2006 to 2008]. Following, I joined a firm under a statutory board involving in National Security Frameworks as a Senior Consultant [2009].

I would like very much to meet altrulistic, courageous, purposive, perspicacious people who are seeking to work on a noble cause. It is a very nourishing experience to share life lessons with compassionate, passionate people who are relentlessly seeking discoveries and growth.

Professional profile:
http://linkd.in/MichaelElijah

My Teachers:
[1] http://bit.ly/ProfessorDavidAkopian
[2] http://bit.ly/ProfessorSosAgaian
[3] http://bit.ly/ProfessorArtyomGrigoryan
[4] http://bit.ly/ProfessorErMengHwa
[5] http://nanyang.academia.edu/DanielTan

[6] http://bit.ly/ProfessorRuanJianhua
[7] http://bit.ly/ProfessorFredHudson
[8] http://bit.ly/ProfessorByeongKilLee
[9] http://bit.ly/ProfessorJinYufang
[10] http://bit.ly/ProfessorFengYusheng

Professional Interests:

 

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Files Posted by Michael View all
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(last 30 days)
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23 Jul 2014 Screenshot Modular Exponentiation y = x^e mod n Author: Michael Chan arithmetic, modular exponentiatio... 41 0
30 Jun 2014 Screenshot Convert Image To And From Graph Coordinates Illustrates mapping of binary image to graph coordinates and vice-versa. Author: Michael Chan image, plot, coordinates, geometry, graph, mapping 51 0
  • 2.0
2.0 | 1 rating
24 Jun 2014 Screenshot Using Gauss' Algorithm to solve simultaneous linear congruences for Chinese Remainder Theorem Gauss' Algorithm to solve for Chinese Remainder Theorem (CRT) Author: Michael Chan number theory 24 1
11 Jan 2013 Screenshot Simple Object Creation in Matlab Object Oriented Programming (OOP) The objective is to provide a simple sample code to illustrate OOP in Matlab. Author: Michael Chan oop, objectoriented progra..., data formatting, interpretator 21 0
21 Jun 2012 Screenshot Image Description Notes (with LSB encoding) The objective is to illustrate how certain reference may be made to a given image. Author: Michael Chan text, bit, data hiding, description, profile, lsb 28 1
Comments and Ratings by Michael View all
Updated File Comments Rating
26 Jun 2014 Wavelet Decomposition For Images The demo decouples the wavelet operations from the plotting. Author: Michael Chan

Hi Mehdi,
You can extract the coefficients at different levels as an obversation with any existing image(s). Would you have a wavelet feature extraction algorithm in mind or a paper you have referred to?

22 Jun 2014 Using Gauss' Algorithm to solve simultaneous linear congruences for Chinese Remainder Theorem Gauss' Algorithm to solve for Chinese Remainder Theorem (CRT) Author: Michael Chan

Number of linear congruences to be extended in the next update.

20 Jan 2013 arrow.m Draw a line with an arrowhead. Author: Erik Johnson

How do you turn off the arrow heads at either ends of the start and stop points?

16 Jan 2013 Wavelet Decomposition For Images The demo decouples the wavelet operations from the plotting. Author: Michael Chan

Hi Rewati, it is. It's a form of lossy compression where you keep only the coefficients of the Approximate region(s).

01 Jun 2012 Wavelet Decomposition For Images The demo decouples the wavelet operations from the plotting. Author: Michael Chan

Hi Diógenes Diógenes,

Did you run the observeWaveletDecompositionBenchmark_N_levels.m file? As stated in the readme.txt, it is the main executing reference usage file.

For a single decomposition level, set

levelOfDecomposition = 1; % level N = 1

For the inquiries regarding the variables, in image wavelet decomposition, the segments are divided according to the (H)orizontal, (V)ertical, (A)pproximate and (D)iagonal regions.

Usually, the coefficients are represented in the form (in the example of 1 level wavelet decomposition):
coeff_A1, coeff_H1;
coeff_V1, coeff_D1;

I hope that helps.

Comments and Ratings on Michael's Files View all
Updated File Comment by Comments Rating
26 Jun 2014 Wavelet Decomposition For Images The demo decouples the wavelet operations from the plotting. Author: Michael Chan Chan, Michael

Hi Mehdi,
You can extract the coefficients at different levels as an obversation with any existing image(s). Would you have a wavelet feature extraction algorithm in mind or a paper you have referred to?

22 Jun 2014 Using Gauss' Algorithm to solve simultaneous linear congruences for Chinese Remainder Theorem Gauss' Algorithm to solve for Chinese Remainder Theorem (CRT) Author: Michael Chan Chan, Michael

Number of linear congruences to be extended in the next update.

12 Jun 2014 Wavelet Decomposition For Images The demo decouples the wavelet operations from the plotting. Author: Michael Chan hym, mehdi

Hi Michael Chan,first of all i thanking you for this usefull code , so in my application(hand vein recognition pattern) i need to use wavelet like feature extraction in order to classify data,so if give me a hand Mr Michael.

21 May 2014 File Ordering Patch Utility for MATLAB The utility patches the reordering considering the length of the filename during the sorting. Author: Michael Chan Cobeldick, Stephen

This submission is a very neat idea (thus the two stars), but it is let down by the code (thus the two stars). In particular, this submission:
- changes the input data multiple times between char and cell of strings arrays.
- uses unnecessary "for" loops… and changes the data type inside the loops (just use indexing!).
- concatenates the strings one-by-one to generate the output... with no array pre-allocation.
- has multiple "mlint" messages that need attention.
- include many lines of commented-out code.
- has misleading variable names: "sortedIndex" actually contains the string data itself.
- no help section, no information on the input or output specifications.
- unnecessary "sort": "unique" returns sorted data anyway.
- changes the input data type from cell of strings to output a char array.
- uses multiple files… for such a simple concept.

In fact the algorithm concept is simple enough, and here it is implemented in four lines of code plus input checking, with no loops and it keeps the input array orientation at the output:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function out = resortFileOrder5(inp)
% Simplified "resortFileOrder.m" that implements exactly the same sort concept without loops, and just five lines of code.
assert(iscellstr(inp),'Input must be a cell array of strings.')
tmp = sort(inp(:));
loes = cellfun('length',tmp);
swltc = arrayfun(@(n)tmp(n==loes),unique(loes),'UniformOutput',false);
out = reshape(vertcat(swltc{:}),size(inp));
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

And as I noted below, by using a different concept this submission could be simplified into two lines of code plus input checking (and does not create multiple internal variables):
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function out = resortFileOrder2(inp)
% Simplified "resortFileOrder.m" in just two lines of code.
assert(iscellstr(inp),'Input must be a cell array of strings.')
[~,idx] = sortrows([cellstr(char(32+cellfun('length',inp))),inp]);
out = reshape(inp(idx),size(inp));
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

It is worth noting that this submission does NOT provide a natural order sort. If your data has leading zeros, if the numbers are located in different positions in the strings or has multiple numeric values inside the strings then this concept might not work:
temp = {'test2part2', 'test10part2','test1part10','test1part9'};
resortFileOrder(temp)
ans = […
'test1part9 ';
'test2part2 ';
'test10part2';
'test1part10']

As was mentioned by Douglas Schwarz below, there are other submissions on FEX that provide natural order sorting, eg using the above test data:
sortnat(temp)
ans = {'test1part9','test1part10','test2part2','test10part2'}

You can find Douglas Schwarzes natural order sort here:
http://www.mathworks.com/matlabcentral/fileexchange/10959
and my own customizable natural order sort here:
http://www.mathworks.com/matlabcentral/fileexchange/34464

14 May 2014 File Ordering Patch Utility for MATLAB The utility patches the reordering considering the length of the filename during the sorting. Author: Michael Chan Cobeldick, Stephen

Note: my comment below assumes a cell array of strings.

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