Lunes, Marso 5, 2012

Mango – Windows Phone 7 from Microsoft

Mango is the name of new Windows Phone 7 from Microsoft and it was released to the manufacturers for OS testing and compatibility.
It will probably be available in a few weeks in Japan first (by Fujitsu), then lately by Nokia, Samsung, LG and HTC.
Let’s sneak a bit in the phone and see – of course – what’s different? Microsoft is not bringing brand new revolutionary features on the market (at least not all of them…), but it makes them smarter and easier to access.
To start with, the home screen – it is actually the Start Screen. So you can stay up to date with everything you want to know (depending on the applications that you are interested). For example: weather, friends’ social status, emails, calls, agenda or texts.

Microsoft is launching the hub term in its Windows Phone 7. So it has:

- People Hub: referring to friends, there is not just a list of contacts. Windows Phone 7 integrates a person’s Facebook, Twitter, LinkedIn and Windows Live profiles and tells you right up to date everything that is new for each person in your list.
- Similar to this is unification of the messaging inbox, which allows the user to easily see all the text he receives, but in a smart way, divided in personal (social network messages, personal email accounts and so on) and business (Outlook)
- Pictures Hub: collects your entire taken photos (which you can shot even if the phone is locked!) and even your friends’ posted photos on the social networks.
- Games Hub: besides playing whatever game you desire, you can create a gamer profile and go online through Xbox live to meet other gamers. Your scores will always be remembered!
- Media Hubs: music and video collections, among PC wireless synchronization.
- Office Hub: because it is the only phone with Office Mobile, Windows Phone 7 is detaching you from your PC: you can reach all you need: from Word, Excel and PowerPoint to OneNote and SharePoint.
- Marketplace Hub
One of the breakthroughs is the built in Bing, which helps the user with maps and search. The search actually does the work for you:
- It can scan a bar code and find any related thing you would want to know about that particular item: where does it come from, where can you find it, what does it contains, what is the price, reviews, etc.
- It can locate you and suggest to you: nearest places to visit, or nearest restaurants, shopping center, trains, locations – it is a life saver!
As a browser it uses IE9, it runs instantaneously and it is multitasking.
Last but not least, it has the smart possibility to Find Phone – if you lose your phone, you can remotely write a massage on it, locate it, lock it or erase things.

Information technology

Information Technology (IT) is concerned with technology to treat information. The acquisition, processing, storage and dissemination of vocal, pictorial, textual and numerical information by a microelectronics-based combination of computing and telecommunications are its main fields. The term in its modern sense first appeared in a 1958 article published in the Harvard Business Review, in which authors Leavitt and Whisler commented that "the new technology does not yet have a single established name. We shall call it information technology (IT).". Some of the modern and emerging fields of Information technology are next generation web technologies, bioinformatics, cloud computing, global information systems, large scale knowledgebases, etc. Advancements are mainly driven in the field of computer science.

Technology

IT is the area of managing technology and spans wide variety of areas that include computer software, information systems, computer hardware, programming languages but are not limited to things such as processes, and data constructs. In short, anything that renders data, information or perceived knowledge in any visual format whatsoever, via any multimedia distribution mechanism, is considered part of the IT domain. IT provides businesses with four sets of core services to help execute the business strategy: business process automation, providing information, connecting with customers, and productivity tools.

IT professionals perform a variety of functions (IT Disciplines/Competencies) that ranges from installing applications to designing complex computer networks and information databases. A few of the duties that IT professionals perform may include data management, networking, engineering computer hardware, database and software design, as well as management and administration of entire systems. Information technology is starting to spread further than the conventional personal computer and network technologies, and more into integrations of other technologies such as the use of cell phones, televisions, automobiles, and more, which is increasing the demand for such jobs.

Lunes, Pebrero 20, 2012

SORTING

Research an application or scenario that the following sorting algorithms can be applied (include a description and an image):

Bubble sort - often incorrectly referred to as sinking sort, is a simple sorting algorithm that works by repeatedly stepping through the list to be sorted, comparing each pair of adjacent items and swapping them if they are in the wrong order.

Selection sort - is a sorting algorithm, specifically an in-place comparison sort. It has O(n²) time complexity, making it inefficient on large lists, and generally performs worse than the similar insertion sort.

Insertion sort - is a simple sorting algorithm: a comparison sort in which the sorted array (or list) is built one entry at a time.

Shell sort - also known as Shell sort or Shell's method is an in-place comparison sort.

Bucket sort or bin sort - is a sorting algorithm that works by partitioning an array into a number of buckets.

Merge sort - is an O(n log n) comparison-based sorting algorithm.

Quick sort - is a sorting algorithm developed by Tony Hoare that, on average, makes $O (n log n)$ comparisons to sort n items.

Lunes, Enero 30, 2012

TOPIC

Sorting is any process of arranging items in some sequence and/or in different sets, and accordingly, it has two common, yet distinct meanings:

ordering: arranging items of the same kind, class, nature, etc. in some ordered sequence,
categorizing: grouping and labeling items with similar properties together.

Selection sort is a sorting algorithm, specifically an in-place comparison sort. It has O(n²) time complexity, making it inefficient on large lists, and generally performs worse than the similar insertion sort. Selection sort is noted for its simplicity, and also has performance advantages over more complicated algorithms in certain situations, particularly where auxiliary memory is limited.

Selection sort can also be used on list structures that make add and remove efficient, such as a linked list. In this case it is more common to remove the minimum element from the remainder of the list, and then insert it at the end of the values sorted so far. For example:

64 25 12 22 11

11 64 25 12 22

11 12 64 25 22

11 12 22 64 25

11 12 22 25 64

/* a[0] to a[n-1] is the array to sort */
int iPos;
int iMin;
 
/* advance the position through the entire array */
/*   (could do iPos < n-1 because single element is also min element) */
for (iPos = 0; iPos < n; iPos++) {
    /* find the min element in the unsorted a[iPos .. n-1] */
 
    /* assume the min is the first element */
    iMin = iPos;
    /* test against all other elements */
    for (i = iPos+1; i < n; i++) {
        /* if this element is less, then it is the new minimum */  
        if (a[i] < a[iMin]) {
            /* found new minimum; remember its index */
            iMin = i;
        }
    }
 
    /* iMin is the index of the minimum element. Swap it with the current position */
    if ( iMin != iPos ) {
        swap(a, iPos, iMin);
    }
}

Mathematical definition

Let

L

be a non-empty set and $f : L \to L$ such that

f (L) = L'

where:

$L'$ is a permutation of $L$ ,
$e_i \le e_{i+1}$ for all $e \in L'$ and $i \in \mathbb{N}$ ,
$f(L) = \begin{cases} L, & \mbox{if }|L| = 1\\ \{s\} \cup f(L_{s}), & \mbox{otherwise} \end{cases}$ ,
$s$ is the smallest element of $L$ , and
$L s$ is the set of elements of $L$ without one instance of the smallest element of $L$ .

Analysis

Selection sort is not difficult to analyze compared to other sorting algorithms since none of the loops depend on the data in the array. Selecting the lowest element requires scanning all n elements (this takes n − 1 comparisons) and then swapping it into the first position. Finding the next lowest element requires scanning the remaining n − 1 elements and so on, for (n − 1) + (n − 2) + ... + 2 + 1 = n(n − 1) / 2 ∈ Θ(n²) comparisons (see arithmetic progression). Each of these scans requires one swap for n − 1 elements (the final element is already in place).

New Technology

As the 5th generation of the iPhone is on the verge of being released, and with all the speculations spreading on the Internet about the iPhone 5, people are anticipating and desperately waiting for the launch of the smartphone, which is now expected to happen in Summer 2012. Many fans and current Apple iPhone consumers are wondering what groundbreaking features Apple will add to the new iPhone 5.
UPDATE: The most recent rumors indicate that the iPhone 5 will have a 4+ inch display, possibly made by Korean giant LG. However rumors of a teardrop-shaped device have been shelved after a Foxconn employee in China revealed that samples so far are symmetrical in thickness. (Foxconn is the company that currently manufactures the iPhone 4S and iPad 2 for Apple.) The same source reveals that neither of the samples have the iPhone 4 and iPhone 4S forms, and that neither of the devices seen so far are the final versions. This employee has however failed to indicate any concrete features that are set to appear in this next generation of iPhone.
This article summarizes the various features and specifications that are expected to sport the device.

iPhone 5 Features

Although Apple does not reveal the exact specifications and features until the device is officially unveiled, we could dictate some of the main features that are expected. However, rumor of the new iPhone 5 features, in terms of both hardware and software upgrades, will definitely entice any smartphone buyer. The upcoming phone is expected to sport the Apple’s latest and greatest A5 processor chip, iCloud service, higher-resolution camera, and a 4+ inch screen size. Here are some of the most anticipated iPhone 5 features:

iOS 5

Apple announced iOS 5.0 and its features during the WWDC 2011 keynote address on June 6, 2011. The user interface is based on the concept of direct manipulation, using multi-touch gestures. It is expected to come with more than 200 new features that will include improved Notification System, News Stand and iMessage.
iMessage is an application that is developed to compete with Blackberry Messenger. The app will allow iPod Touch, iPhone, and iPad users to communicate (much like a chat service) with each other. The iMessage feature has been integrated into the SMS/MMS application used originally on the iPhone models.
iPhone 5

iCloud

The iPhone5 is expected to have the iCloud service.
Apple’s iPhone 5 is expected to feature the new iCloud service for wireless remote access of music from all computers and mobile devices.
The iPhone5 will automatically sync with the iCloud which will allow users to store photos, apps, calendars and documents without having them to store in the phone’s memory. Apple is also looking to tie up with top music label companies to license songs for the iCloud service.
However, rumors state that Apple might release a low-cost “iCloud iPhone” alongside the iPhone 5. It could be named the “iPhone Mini”

“The iPhone Mini (or iPhone Nano, or whatever) could have significantly less storage than a typical iPhone. Most likely 8 gigabytes of storage – the same as the lowest end iPhones right now. Apple won’t prevent users from storing their own content, because that would be crazy. But since it has a small amount of memory, Apple will likely push the ability to stream media via MobileMe as well.”

A5 Processor to power the iPhone5

iPhone 5 will house the A5 as the main processor, which technically is the same chip that currently powers the iPad 2. The A5 contains a dual-core ARM Cortex-A9 CPU with NEON SIMD accelerator and a dual core PowerVR SGX543MP2 GPU, which means that the iPhone5 can do twice the work at once. The processor speed will be somewhere between 1.2 to 1.5 GHz, with probably a 1GB RAM.
The processor upgrade is done not just to increase the processing speed of the phone, but also to compete with the newly launched Samsung Galaxy S II.
The A5 chip might effectively increase the power use, however, it is said that the chip has “got a dynamic power management”, which can lower the [speed] depending on the workload, and thus efficiently make use of the power.

iPhone 5 to Sport a Better Camera

The iPhone 4 sports a 5 megapixel camera, so I’m expecting that the iPhone 5 will have a rear-facing 8MP dual-LED flash camera. However, this isn’t really “awesome”, since most of the high-end Android smartphones come with an 8MP camera. Along with that, the iPhone 5 is expected to have a front-facing camera for video chatting.
iPhone Features

According to sources, Apple has filed several patent applications relating to 3D picture capturing to the US Patent and Trademark Office later in March. This indicates that the iPhone 5 might feature a 3D camera. The filing indicates that the device will be capable of capturing, processing and rendering 3D images with dual-camera hardware.
Another interesting feature is that the iPhone 5 will be capable of taking pictures in Panorama. It will work similarly to the ’360 Panorama’ application in the App Store. It will let you take pictures in a sequence as you move the camera from one side to another, which in the end will effortlessly stitch the images together to create a panorama.
Additionally, if Apple really wants to keep up with the competition to Android, then it might consider improving upon the video resolution to a full 1080p HD recording. Currently iPhone 4 has a 720p video capture at 30 frames per second.

Display and Resolution

There hasn’t been a better screen resolution since the release of the iPhone 4. Currently the iPhone 4 has a 3.5 inches screen size, and sources indicate that Apple might stay locked with the current size. But a few other sources (including a recent rumor from a Foxconn employee in China) say that Apple is planning to increase the screen size to 4+ inch with higher screen resolution.

Image credits: PhoneArena.com However, the iPhone 5 could be slightly wider and thinner. The dimensions are calculated to be: 4.33″ x 2.36″ and .27″ thickness at the top and .21″ at the bottom, whereas the dimensions of iPhone 4 are: 4.5″ x 2.31″ x .37″

Other iPhone5 Features

Here are some of the other features that we can expect from the iPhone 5:

Other iPhone 5 Features

Face Recognition Security
4G/LTE support *
A new, sleeker body design
OLED screen
Scratch proof and shatter proof screen
Wireless sync with iTunes
Extended battery life
Flash support
SIM-less phone **
Physical keyboard
Increased RAM (from 512MB to 1GB)
New multi-tasking look
HD audio
Built-in GPS

(*) According the AT&T documents leaked by LulzSec, the Apple iPhone 5 will offer 4G and will be LTE (Long Term Evolution) network compatible. LTE is a project of the 3rd Generation Partnership Project (3GPP), and is the latest standard in the mobile network technology.
(**) According to International Business Times, it is rumoured that the iPhone 5 will feature a new SIM-less design with 2 to 3 internal antennas for CDMA and GSM compatibility, which will make it a “worldphone”.
The above mentioned features are some of the improvements that we can expect from Apple. However, we cannot assure you that they can be true, but most of the upgrades are more likely to be utilized.
Apple definitely wants to fight back against Android smartphone makers like HTC and Samsung, and perhaps it is why the new iPhone 5 will host some of the outstanding features.

iPhone 5 Launch Date

Apple follows a tradition to launch new devices in their summer Worldwide Developers Conference (WWDC), but that didn’t happen this year.
However, BGR reported that an AT&T Vice President has confirmed to several employees that the iPhone 5 that boasts a stronger chip for processing data and a more advanced camera is scheduled to be launched in early October. Additionally, the VP communicated the following to a group of managers: “Expect things to get really, really busy in the next 35-50 days, so prepare your teams accordingly.”
We can expect the announcement of the iPhone 5 later this year, possibly at the 2012 edition of Apple’s Worldwide Developers Conference (WWDC), which is likely to take place in June 2012. The release date would then be set for a few months later.
The iPhone 4 has proven to be one of the most successful smartphones of all time with selling over 1.7 million devices in just three days of availability, and iPhone 4S sales hit the roof with more than 600,000 units sold on the first day. We are expecting that the iPhone 5 will certainly replicate this success, and one thing is for sure – the sales of iPhone 5 will definitely boom and we can expect a huge number of people lined up at Apple stores when the device is available for sale.

iPhone 5 Price

At this stage no official price has been unveiled but we expect the iPhone 5 to be the same price than the iPhone 4S when it was released. We will update this section as soon as we have more information on that topic.
What do you think of iPhone 5? Will you buy it? What additional iPhone 5 features are you expecting? Please let us know by leaving your comments below. If you want to read our review of the iPhone 4S, please click this link: iPhone 4S.

Lunes, Enero 16, 2012

Case Study 5

Give at least three scenarios in the real world wherein HASH COLLISION can happen. Include an image.

Case Study 4

We already discuss hash functions..

Answer the following questions:

1. What is hash collision?
Hash collision is a situation that occurs when two distinct pieces of data have the same hash value, checksum, fingerprint, or cryptographic digest.

2. What really happens during a hash collision? Include an image

It depends on the application. When hash functions and fingerprints are used to identify similar data, such as homologous DNA sequences or similar audio files, the functions are designed so as to maximize the probability of collision between distinct but similar data. Checksums, on the other hand, are designed to minimize the probability of collisions between similar inputs, without regard for collisions between very different inputs.

3. What are the ways and methods to resolve hash collision? Explain Each
Find a free slot in the hash table when the home position for the record is already occupied. We can view any collision resolution method as generating a sequence of hash table slots that can potentially hold the record. The first slot in the sequence will be the home position for the key. If the home position is occupied, then the collision resolution policy goes to the next slot in the sequence. If this is occupied as well, then another slot must be found, and so on. This sequence of slots is known as the probe sequence, and it is generated by some probe function that we will call p.