Programming : Sorting (Maximum/Minimum Sorting)

This sorting method called sequencing Maximum / minimum because it is based on the selection of elements of maximum / minimum as a base sequencing. The idea is to choose the elements of maximum / minimum element then swap it with the element farthest Array (element left end or right end).

Subsequently repeated in the same way for the remaining array elements with no longer includes elements that have been ordered array.

Suppose the array elements will be sorted ascending:
Step 1: Determine the maximum price in the L [1 .. N] maximum price Interchange with L [N]

Step 2: Determine the maximum price in the L [1 .. N-1] Interchange maximum price with L [N-1]

Step 3: Determine the maximum price in the L [1 .. N-2] Interchange maximum price with L [N-2]. .

Step N-1: Determine the maximum price in the L [1 .. 2] Interchange maximum price with L [2]

Remaining element is L [1] does not need to be sorted because it is the last element.
So at each step there is a sorting process of finding the maximum price checkers exchange process a two-element array. Number of sorting steps is N-1.

For example : 
Given an Array instance with N = 6 pieces Ascending elements not, this array will be sorted ascending. Element of the array is 25, 27, 10, 8, 76, 21

Programming : Sorting (Bubble Sort)

Ordering is the process of arranging a set of objects in a particular order or arrangement. The object can be an ascending sequence (Ascending) or decreased (Descending). The sorted data  has many advantages, among others:
1. Speed ​​up the search process
2. Can be easily determined maximum and minimum ordering process
There is a need to bring a variety of sorting methods which aim to obtain optimal sorting method.

Sorting algorithms which are widely recognized among others:
1. Bubble Sort (Sorting Bubble)
2. Insertion Sort (Sorting Insert)
3. Maximum / Minimum Sort
4. Heap Sort
5. Shell Sort
6. Quick Sort
7. Merge Sort
8. Radix Sort
9. Tree Sort


For all the sorting algorithms that will be discussed later using the type Array (Array),
which is defined as follows:
{Declaration}
Const NMaks = 100 //Maximum Number of elements {Array}
Type LarikInt = array [1 ... NMaks] of integer

In this post, we will discuss only three sorting methods, namely:
1. Ordering Bubbles (Bubble Sort) 
Ordering bubble inspired by soap bubbles are above the water surface. Because soaps are lighter specific gravity than water density, it will always be soap bubbles floating on the surface. The principle of flotation is used in bubble sort. Array elements are the most precious little "float", meaning lift up (or to the left end of the array) through a process of exchange, if it will do sorting enlarged, if ordering smaller otherwise.

Fuzzy Logic

Fuzzy
Fuzzy System has been existed since 1920, that proposed by Lukasiewicz. Fuzzy System existed to handle gray interpretation, which means to handle variable that have non-crisp values or bold values (crisp values : True/False). Fuzzy System likely more handling the variable that have non-crisp value or we called degrees of membership, for example the variable that has values between 0..1

"FUZZY LOGIC IS A BRANCH OF THE MEMBERSHIP DEGREES COMPARED USING EXPRESS MEMBERSHIP (TRUE / FALSE)"

Fuzzy Logic
Fuzzy Logic more focused on quantitying and reasoning of fuzzy that comes from natural language. Value that comes from natural language is more known as Linguistic Variable / Fuzzy Variable . For example above

Fuzzy

Fuzzy Rule
On Fuzzy System, Linguistic Variable is used on Fuzzy Rule. Example of Fuzzy Rule :

Fuzzy Rule

Fuzzy Membership & Fuzzy Sets
In crisp logic, we just have 2 values, True and False, but in Fuzzy, we have membership degrees, or range 0 to 1 in values.
To make Fuzzy Sets, we need the membership function. To define membership function, there are many methods, for example : polling, define itself, questioner, etc. Example of fuzzy : Short (4..6) Medium (4,5..6,5) Tall (5..7) and the fuzzy sets are like this :

Fuzzy Sets

Fuzzy Time Series

Fuzzy Time Series is one of method that usually used for predicting. Fuzzy Time Series is combining of data time series and using fuzzy logic to create prediction for what's next. In Fuzzy Time Series the data that used is data time series, which is have many time sequences of data, and the variable can be only one. For example : Sales Total of Dept. Store X in 2000 - 2010. It's contain only 1 variable data which is Total Sales, but it has many sequence data, for example : per month, year.

To use this method, simply find the data that have sequence time,or we called data time series, then preprocessing the data, then using this Fuzzy Time Series to predict. We can preprocess data with many ways, for example : using Min-Max Normalization and Z-Score Normalization. This preprocessing is done for making the data better. In Fuzzy Time Series, it will be good, if the differences (lag) between data is not too high, because it will take effect on the prediction.

Well after the data being processed, simply use this method. There are many steps of Fuzzy Time Series. First step, Making the Interval.
The interval is determined by look at the data. We should find the data maximal, minimal, lag between data, and average of lag.After we find these attributes, we can calculate data by Range/(Avg.lag/2). Range is Dmax - Dmin.

Mobile malware is increasing

Cyber ​​threats are increasingly mushrooming. In addition to viruses or malware, phishing threats also continue to lurk in the internet users around the world, including Indonesia.
It says Business Development Manager Kaspersky Lab Southeast Asia Dony Koesmandarin, with the increasing number of smartphone users grows, the threat to users has now spread to mobile devices, such as cell phones and tablet PCs.

Scientists create invisibility viewing tools!

Google Glass function less 'horrible'? This technology may make some people more frightened. Because, with this device people can see invisibility.
Scientists from the Massachusetts Institute of Technology (MIT) experimented with a system they called Wi-Vi. The system is able to track objects moving behind the wall, using the wireless system is fairly inexpensive and readily available everywhere.

Wi-Vi can be embedded in a smartphone or handheld device specific. Dina Katabi, professor who developed the Wi-Vi with students Fadel Adib said, this system will be used for legal purposes or rescue during a natural disaster.
However, according to Katabi, users can use the gadget. For example, when a person is concerned there are following or stalking from behind, he could use gadgetnya to detect whether or not there are people behind the wall.

PHP Basic - Casting, Variable, Constants, Error Controlling Operator

After reading these post : PHP basic 1 and 2, i'd like to continue to add more basic on PHP. This time i will adding some basic on casting, variable, constants, and operator.

Casting
PHP can cast data automatically, for example :

<?php
$a = 15;
$b = '2';
$times = $a*$b;
echo $times;
?>

As you see $a is integer and $b is string, but PHP change the string into integer automatically, because the string also number. It can happen only if the inside string is integer type.

Moreover, we can manually casting the variable, for example:

<?php
$a = 15;
$b = 4;
$times = $a/$b;
$casttimes = (int) $times;
echo "before cast : $times<br>";
echo "after cast to integer :$casttimes";
?>

Try to run it, $times will display 3.75 which is float type, and after cast to integer, it will display 3 only. We can cast into data types that available in PHP, which is :

- (int) (integer) : cast into integer

- (float) (double) : cast into float

- (string) : cast into string

- (object) : cast into object

- (array) : cast into array

Variable

- Predefined Variable

We have learned about variable at last post, well there are some predefined variable, that provided by PHP :  

* $_SERVER
To access variable that available in server
* $_POST
To take data from form or HTTP POST
* $_GET
To take data from url
* $_COOKIE
To take data from cookies that stored in web
* $_FILES

To take data from HTTP POST files.

We will use mostly $_POST when we creating web. It's useful when used with form.

- Variable Variable

What's this? sounds weird huh? Yap, this is one rule that apply too in PHP. To understand more, let's take a look at this example :

<?php
$a = 'Alex';
$$a = 'Oxlade';
$$$a = 'Chamberlain';
echo $a."<br>";
echo $$a."<br>";
echo $$$a."<br>";
?>

As you see in code above,  $$a is same as $alex, which is, $alex is still null, and we fill it with 'Oxlade', and when we want to display it, just type $$a, and it will display Oxlade. Same implements that work in $$$a.