Mobile OS – Operating systems

The new operating systems are able to transform a mobile phone into a complete multimedia device. Until a short time ago, the selection of a mobile phone was determined by its physical features: Signal reception, camera, size, weight… but, nowadays, the selection of an operating system has become a fundamental thing, especially when choosing a smartphone.



We want to help you have a clearer vision of the general characteristics by listing four key aspects (interface, apps, phones, future) of the seven most used operating systems today.


Android 2.0


* Interface: It is very similar to the Apple one but, at this time, the system seems an OS in an early version, which needs more improvements.


* Apps: More than 65,000 applications and many of them (about 50%) are free.


* Phones: There is a wide variety of mobile phones with Android including Nexus 1, Motorola Milestone, some HTC mobile phones, and some Samsung phones, among others.


* Future: With a continuous growth, it seems that the Android OS will be competing with Symbian to become the world leader in the market segment that don’t use Apple.


Apple OS 3.1


* Interface: Intuitive and easy to use. It has become an important reference for the touch screens adoption in the smartphones market.


* Apps: It offers more than 225,000 applications, which are available in the Apple Store (a chain of retail stores owned and operated by Apple Inc.)


* Phones: It is used in the iPhone, but it is also used in other gadgets such as the iPod Touch and the iPad.


* Future: A very promising future.



Maemo 5


* Interface: It allows the use of several applications at the same time (multitasking).


* Apps: When compared to other operating systems, this OS has few applications, especially regarding downloadable applications.


* Phones: It is used in the Nokia N900. Also, it is used in other different devices such as the Nokia Internet “tablet”.


* Future: Maemo has teamed with Moblin (Mobile Linux) to create the MeeGo platform.

Palm Web OS

* Interface: Along with the Apple OS, this is the operating system with a more developed and advanced interface and, at the same time, it looks very different to the iPhone interface.


* Apps: It has around 1,500 available applications with a very good performance and quality. They can be downloaded through the Palm App Catalog.

* Phones: It is used in the Palm Pre and the Palm Pixi.


* Future: In spite of its great features, the competition with other platforms is a very difficult thing due to the pretty small market share of Palm. So, the future doesn’t look too bright.


RIM OS V5.0

* Interface: The user interface has the typical appearance of a UI for a “sober” phone without many additional ornaments. Anyway, in general terms, it is still very user-friendly.


* Apps: It has about 6,000 applications, although some of them are a little old.


* Phones: It is an exclusive system for the Blackberry brand.


* Future: Perspectives are good, at least in the immediate future. Blackberry is not precisely a current remarkable star of the market, but its market share is quite stable with few variations.


Symbian ^1 OS
* Interface: Sometimes, there are some necessary steps that are not very user-friendly because they are complex, at least for average (or novice) users.


* Apps: Besides the available applications that can be accessed through Symbian Horizon, the makers of mobile phones have added other apps. For example: Nokia has more than 9,500 apps for Symbian, which are available in the Nokia OVI Store.


* Phones: Several versions of Symbian are present in many mobile phones with different brands (Nokia, Sony, Samsung, etc.) We can say it is a popular operating system.


* Future: Symbian continues being the leader in the market with the bigger market share. However, at this time, its more advanced functions are less used than the advanced functions of the iPhone and Android phones.


Windows Mobile 6.5

* Interface: It still uses a structuring that seems derived from the PCs, instead of looking like an interface that was designed originally to be used in mobile devices.

* Apps: A short while ago, users were allowed to download applications directly to the mobile phones through the MarketPlace.


* Phones: It is used in mobile phones like HTC HD2, Samsung Omnia II, Acer Neo Touch and other phones of different makers.


* Future: Some months ago, Microsoft presented a new version of this OS: Windows Mobile 7 (rebranded as Windows Phone), which has not been officially launched yet. There are some rumors circulating about compatibility issues with the current version.

"Skinput" turns body into touchscreen interface
(Tapping on arm allows users to scroll through menus and select options)







Touchscreens may be popular both in science fiction and real life as the symbol of next-gen technology, but an innovation called Skinput suggests the true interface of the future might be us.


Microsoft and Carnegie Mellon University unveiled Skinput recently, showing how it can turn your own body into a touchscreen interface.


Skinput uses a series of sensors to track where a user taps on his arm. Previous attempts at using projected interfaces used motion-tracking to determine where a person taps.

Skinput uses a different and novel technique: It "listens" to the vibrations in your body.


Tapping on different parts of your arm creates different kinds of vibrations depending on the amount and shape of bones, tendons and muscle in that specific area. Skinput sensors can track those vibrations using an armband and discern where the user tapped.


"Accuracy is already good, in the high 90s percent accuracy for finger input," said project team member Chris Harrison, from Carnegie Mellon's Human-Computer Interaction Institute.


"The arm band is a crude prototype,” Harrison said. “The next generation could be made considerably smaller – likely easily fitting into a wristwatch."

To Know about the basic of DBMS......

QUESTION :What is database?

ANSWER:

A database is a logically coherent collection of data with some inherent meaning, representing some aspect of real world and which is designed, built and populated with data for a specific purpose.

QUESTION :What is DBMS?

ANSWER:

1. Redundancy is controlled.
2. Unauthorised access is restricted.
3. Providing multiple user interfaces.
4. Enforcing integrity constraints.
5. Providing backup and recovery.

QUESTION :What is a Database system?

ANSWER:

The database and DBMS software together is called as Database system.

QUESTION :Disadvantage in File Processing System?

ANSWER:

1. Data redundancy & inconsistency.
2.Difficult in accessing data.
3. Data isolation.
4.Data integrity.
5.Concurrent access is not possible.
6. Security Problems. .

QUESTION :Describe the three levels of data abstraction?

ANSWER:

The are three levels of abstraction:
Physical level: The lowest level of abstraction describes how data are stored.

Logical level: The next higher level of abstraction, describes what data are stored in database and what relationship among those data.

View level: The highest level of abstraction describes only part of entire database.

QUESTION :Define the "integrity rules"?

ANSWER:

There are two Integrity rules.

Entity Integrity: States that Primary key cannot have NULL value.

Referential Integrity: States that Foreign Key can be either a NULL value or should be Primary Key value of other relation.

QUESTION :What is extension and intension?

ANSWER:

Extension -It is the number of tuples present in a table at any instance. This is time dependent.
Intension - It is a constant value that gives the name, structure of table and the constraints laid on it.

QUESTION :What is System R? What are its two major subsystems?

ANSWER:

System R was designed and developed over a period of 1974-79 at IBM San Jose Research Center . It is a prototype and its purpose was to demonstrate that it is possible to build a Relational System that can be used in a real life environment to solve real life problems, with performance at least comparable to that of existing system.

Its two subsystems are

*Research Storage.
* System Relational Data System.

QUESTION :How is the data structure of System R different from the relational structure?

ANSWER:

Unlike Relational systems in System R
* Domains are not supported
* Enforcement of candidate key uniqueness is optional
* Enforcement of entity integrity is optional
* Referential integrity is not enforced

QUESTION :What is Data Independence?

ANSWER:

Data independence means that the application is independent of the storage structure and access strategy of data*. In other words, The ability to modify the schema definition in one level should not affect the schema definition in the next higher level.

Two types of Data Independence:

*Physical Data Independence : Modification in physical level should not affect the logical level.

* Logical Data Independence : Modification in logical level should affect the view level.

NOTE: Logical Data Independence is more difficult to achieve

hai ....guys....