Popular Posts

Recent Post’s

Showing posts with label Operating System. Show all posts
Showing posts with label Operating System. Show all posts
                 

 Apple CEO Tim Cook recently told customers, the company believed "in telling you up front exactly what's going to happen to your personal information," but computer experts say that's not the case with a novel feature that automatically charges the company users' searches and placement info.





Apple Inc. has begun collecting search query data from the destination bar of its Safari Web browser, according to multiple experts who have analyzed the code. In addition, Apple is collecting the location of users who conduct a search and those queries in the "Spotlight" search function in OS X Yosemite, a fact buried in its terms of inspection and repair.

Yosemite users realized over the weekend that Apple also sends any search made through Safari’s address bar back to its own servers, no matter what search provider its users pick out. Apple is by default collecting every search query entered into its updated Spotlight feature, which awaits for answers on a user’s computer as easily as Web results. The new feature also collects the user’s location information by default, and those who desire to opt-out must individually turn off related settings in both Spotlight and the Safari browser.

Apple's new default data collection is not performed with its users' "clear and conspicuous" consent, according to Dr. Ben Edelman, associate professor at the Harvard Business School. He told International Business Times that Apple’s method of informing customers in a "hidden" disclosure was not in step with what it recently told clients.

“The estimate that [Safari] would pick up this data no matter what you induce as your default search engine is particularly ironic in light of Apple's recent comments on customer privacy,” Edelman said. “These actions seem particularly incongruous to that.”

The new policy stands in complete contrast to Apple’s recent statements regarding user policy, as it enabled default encryption into its latest iPhone and iPad software following the dispersion of a number of photos from celebrities’ iPhones that were stolen from the company’s cloud online storage service.

“we honor your privacy and protect it with strong encryption, plus strict policies that govern how all data is covered,” Apple CEO Tim Cook said in a missive to customers on the seclusion policy in September, which the company published in full on its internet site. “We believe in telling you up front exactly what’s going to happen to your personal information and asking for your permission before you partake in it with us. And if you switch your mind later, we make it easy to quit dealing with us.”

Apple owns the feature turned on by default in its search engine, most of its users will not infer the kind of data collection that’s being conducted, or how to end it, according to Dr. Eric Burger, a computer science prof at Georgetown University. As technology companies recognize the value in information about their users, they increasingly collect it to improve their products or advertisements, he stated.

“This isn’t out of the average, but that doesn’t get it in good order,” Burger said. Apple did not react to multiple requests for commentary on the issue.

Experts state that the iPhone maker is trying to capitalize on its popularity to start gathering the sort of user data that companies like Google have made profitable, only not in a way that’s particularly open and honest to its users. In fact, it’s a “privacy nightmare,” according to computer scientists and Syracuse University professor Dr. Kevin Duh.

“This information is really valuable, and Apple is competing with Google on many fronts,” Du said. “This is one area where they can break into into [the big data] business, but that’s exactly the improper mode to manage it.”

Browsers in a number of existing operating systems do not currently charge a user’s search anywhere other than the intended search engine, Dr. Duo said, having carried on extensive research on the topic. The only time a search that intended for Google or Bing would give way to a third-party was when browsers were infected by Spyware or otherwise compromised.

Apple’s new policy was first identified by GitHub user and Plausible Labs CEO Landon Fuller, who also produced a software designed to freeze the data collection. He also produced a website to spread the software.

“Mac OS X has always respected user privacy by default, and Mac OS X Yosemite should too,” Fuller said on the website. “Since it doesn’t, you can use the code to the left to disable the parts of Mac OS X which are invasive to your privacy.”

There are alternative web-browsers for OS X Yosemite, such as the Mozilla Foundation’s Firefox web browser, which the company sounded out “does not automatically send search queries to Mozilla."


Automatically Collects Safari Searches, User Location In OS X Yosemite

                 

 Apple CEO Tim Cook recently told customers, the company believed "in telling you up front exactly what's going to happen to your personal information," but computer experts say that's not the case with a novel feature that automatically charges the company users' searches and placement info.





Apple Inc. has begun collecting search query data from the destination bar of its Safari Web browser, according to multiple experts who have analyzed the code. In addition, Apple is collecting the location of users who conduct a search and those queries in the "Spotlight" search function in OS X Yosemite, a fact buried in its terms of inspection and repair.

Yosemite users realized over the weekend that Apple also sends any search made through Safari’s address bar back to its own servers, no matter what search provider its users pick out. Apple is by default collecting every search query entered into its updated Spotlight feature, which awaits for answers on a user’s computer as easily as Web results. The new feature also collects the user’s location information by default, and those who desire to opt-out must individually turn off related settings in both Spotlight and the Safari browser.

Apple's new default data collection is not performed with its users' "clear and conspicuous" consent, according to Dr. Ben Edelman, associate professor at the Harvard Business School. He told International Business Times that Apple’s method of informing customers in a "hidden" disclosure was not in step with what it recently told clients.

“The estimate that [Safari] would pick up this data no matter what you induce as your default search engine is particularly ironic in light of Apple's recent comments on customer privacy,” Edelman said. “These actions seem particularly incongruous to that.”

The new policy stands in complete contrast to Apple’s recent statements regarding user policy, as it enabled default encryption into its latest iPhone and iPad software following the dispersion of a number of photos from celebrities’ iPhones that were stolen from the company’s cloud online storage service.

“we honor your privacy and protect it with strong encryption, plus strict policies that govern how all data is covered,” Apple CEO Tim Cook said in a missive to customers on the seclusion policy in September, which the company published in full on its internet site. “We believe in telling you up front exactly what’s going to happen to your personal information and asking for your permission before you partake in it with us. And if you switch your mind later, we make it easy to quit dealing with us.”

Apple owns the feature turned on by default in its search engine, most of its users will not infer the kind of data collection that’s being conducted, or how to end it, according to Dr. Eric Burger, a computer science prof at Georgetown University. As technology companies recognize the value in information about their users, they increasingly collect it to improve their products or advertisements, he stated.

“This isn’t out of the average, but that doesn’t get it in good order,” Burger said. Apple did not react to multiple requests for commentary on the issue.

Experts state that the iPhone maker is trying to capitalize on its popularity to start gathering the sort of user data that companies like Google have made profitable, only not in a way that’s particularly open and honest to its users. In fact, it’s a “privacy nightmare,” according to computer scientists and Syracuse University professor Dr. Kevin Duh.

“This information is really valuable, and Apple is competing with Google on many fronts,” Du said. “This is one area where they can break into into [the big data] business, but that’s exactly the improper mode to manage it.”

Browsers in a number of existing operating systems do not currently charge a user’s search anywhere other than the intended search engine, Dr. Duo said, having carried on extensive research on the topic. The only time a search that intended for Google or Bing would give way to a third-party was when browsers were infected by Spyware or otherwise compromised.

Apple’s new policy was first identified by GitHub user and Plausible Labs CEO Landon Fuller, who also produced a software designed to freeze the data collection. He also produced a website to spread the software.

“Mac OS X has always respected user privacy by default, and Mac OS X Yosemite should too,” Fuller said on the website. “Since it doesn’t, you can use the code to the left to disable the parts of Mac OS X which are invasive to your privacy.”

There are alternative web-browsers for OS X Yosemite, such as the Mozilla Foundation’s Firefox web browser, which the company sounded out “does not automatically send search queries to Mozilla."



Real Time Operating System(RTOS)

1. Introduction to Real-Time Operating Systems
The sections below outline basic concepts and language related to real-time operating systems. Subsequently, you have read through this paper, it is urged that you visit Building a Real-Time System with NI Hardware and Software next to learn more about how National Instruments can help you construct a superior real-time system in as little time as possible.
What is a Real-Time OS?
In general, an operating system (OS) is responsible for managing the hardware resources of a computer and hosting applications that work on the computer. An RTOS performs these chores, but is also specially designed to run applications with very precise timing and a high level of dependability. This can be particularly important in measurement and automation systems where downtime is costly or a program delay could cause a safety risk.
To be considered "real-time", an operating system must have a known maximum time for each of the critical operations that it behaves (or at least be able to insure that maximum most of the time). Some of these operations include OS calls and break handling. The operating systems that can absolutely guarantee a maximum time for these operations are commonly named to as "hard real-time", while operating systems that can only guarantee a maximum most of the time are denoted to as "soft real-time". In drill, these strict categories have limited usefulness - each RTOS solution demonstrates unique performance characteristics and the user should carefully investigate these features.
To fully grasp these concepts, it is helpful to see an example. Think that you are designing an airbag system for a new model of automobile. In this example, a minor mistake in timing (causing the airbag to deploy too early or too late) could be catastrophic and cause harm. Thus, a hard real-time system is required; you need assurance as the system designer that no individual cognitive process will exceed certain timing constraints. On the other hand, if you were to design a mobile phone that received streaming video, it may be ok to lose a modest total of data occasionally even though on average it is important to hold up with the video stream. For this application, a soft real-time operating system may serve.
The main detail is that, if programmed right, an RTOS can guarantee that a program will melt down with very consistent timing. Real-time operating systems do this by providing programmers with a high level of command over how tasks are prioritized, and typically also allow checking to get sure that important deadlines are taken on.
In contrast to real-time operating systems, the most popular operating systems for personal computer utilization (such as Windows) are called general-purpose operating systems. While more in-depth technical data on how real-time operating systems differ from general-purpose operating systems is fed in a section below, it is important to recall that there are advantages and disadvantages to both types of OS. Operating systems like Windows are designed to maintain user responsiveness with many programs and services running (ensuring "fairness"), while real-time operating systems are planned to move critical applications reliably and with precise timing (paying attention to the programmer's priorities).

Important Terminology and Concepts
Determinism: An application (or critical piece of an application) that runs on a hard real-time operating system is referred to as deterministic if its timing can be guaranteed within a certain margin of error.
Soft vs Hard Real-Time: An OS that can absolutely guarantee a maximum time for the operations it performs is referred to as hard real-time. In contrast, an OS that can usually perform operations in a certain time is referred to as soft real-time.
Jitter: The amount of error in the timing of a task over subsequent iterations of a program or loop is referred to as jitter. Real-time operating systems are optimized to provide a low amount of jitter when programmed correctly; a task will take very close to the same amount of time to execute each time it is run.
2. Example Real-Time Applications
Real-time operating systems were projected for two general classes of applications: event response and closed-loop control. Event response applications, such as automated visual inspection of assembly line parts, require a response to a stimulus in a certain quantity of time. In this visual inspection system, for example, each piece must be photographed and studied before the assembly line goes.
By careful programming an application that works on a hard real-time operating system, designers working on event response applications can ensure that a reaction will happen deterministically (within a certain maximum amount of time). Looking at the parts inspection example, using a general-purpose OS could result in a part not been inspected in time - thus delaying the assembly line, pulling the party to be discarded, or sending a potentially defective part.
In contrast, closed-loop control systems, such as an automotive cruise control system, continuous process feedback data to adjust one or more productions. Because each output value depends on treating the input data in a specified amount of time, it is critical that loop deadlines are satisfied in order to ensure that the right outputs are created. What would take place if a sail control system failed to define what the throttle setting should be at a given peak in time? Once once more, hardened real-time operating systems can ensure that control system input data is treated in a reproducible amount of time (with a fixed worst-case maximum).
It should also be noted that many applications that must run for extended periods of time can benefit from the reliability that an RTOS can provide. Because real-time operating systems typically run a minimum band of software rather than many applications and processes at the same time, they are easily suited for systems that require 24-7 operation or where down-time is impossible or expensive.

3. Below the Hood: How Real-Time OSs Differ from General-Purpose OSs
Operating systems such as Microsoft Windows and Mac OS can provide an excellent platform for training and running your non-critical measurement and control applications. Even so, these operating systems are planned for different use cases than real-time operating systems, and are not the ideal platform for racing applications that need exact timing or extended up-fourth dimension. This segment will identify some of the major under-the-hood differences between both types of functioning systems, and explain what you can expect when programming a real-time application. 
Setting Priorities
When programming an application, most operating systems (of whatever type) allow the coder to set a precedence for the overall application and even for different tasks within the application (threads). These priorities serve as a signal to the OS, dictating which operations the designer feels are most significant. The finish is that if two or more tasks are ready to play at the same time, the OS will function the task with the highest precedence.
In practice, general-purpose operating systems do not invariably follow these programmed priorities strictly. Because general-purpose operating systems are optimized to run a mixture of applications and processes simultaneously, they typically turn to make certain that all tasks receive at least some processing time. As a consequence, low-priority tasks may in some cases have their priority boosted above other higher priority projects. This ensures some amount of run-time for each task, simply implies that the designer's wishes are not invariably observed.
In contrast, real-time operating systems fall out the programmer's priorities much more rigorously. On most real-time operating systems, if a high priority task is using 100% of the processor, no other lower priority projects will be given until the higher priority task finishes. Hence, real-time system designers must program their applications carefully with priorities in mind. In a typical real-time application, a designer will place time-critical code (e.g. Event response or a control code) in one section with a real high precedence. Other, less-important code such as logging to disk or network communication may be united with a section with a lower precedence.
Interrupt Latency
Interrupt response time is measured as the measure of time between when a device generates an interrupt and when that device is serviced. While general-purpose operating systems may contain a varying quantity of time to react to a given interrupt, real-time operating systems must assure that all interrupts will be serviced within a certain maximum amount of time. In other words, the interrupt latency of real-time operating systems must be restrained. 
Performance
One common misconception is that real-time operating systems deliver better functioning than other general-purpose operating systems. While real-time operating systems may offer more honest operation in some instances due to less multitasking between applications and services, this is not a pattern. Actual application performance will depend on CPU speed, storage architecture, program characteristics, and more. 
Though real-time operating systems may or may not increase the speed of execution, they can offer a lot more accurate and predictable timing characteristics than general-purpose operating systems.


for more tutorials please goto here.......

Real Time Operating System(RTOS)

Real Time Operating System(RTOS)

1. Introduction to Real-Time Operating Systems
The sections below outline basic concepts and language related to real-time operating systems. Subsequently, you have read through this paper, it is urged that you visit Building a Real-Time System with NI Hardware and Software next to learn more about how National Instruments can help you construct a superior real-time system in as little time as possible.
What is a Real-Time OS?
In general, an operating system (OS) is responsible for managing the hardware resources of a computer and hosting applications that work on the computer. An RTOS performs these chores, but is also specially designed to run applications with very precise timing and a high level of dependability. This can be particularly important in measurement and automation systems where downtime is costly or a program delay could cause a safety risk.
To be considered "real-time", an operating system must have a known maximum time for each of the critical operations that it behaves (or at least be able to insure that maximum most of the time). Some of these operations include OS calls and break handling. The operating systems that can absolutely guarantee a maximum time for these operations are commonly named to as "hard real-time", while operating systems that can only guarantee a maximum most of the time are denoted to as "soft real-time". In drill, these strict categories have limited usefulness - each RTOS solution demonstrates unique performance characteristics and the user should carefully investigate these features.
To fully grasp these concepts, it is helpful to see an example. Think that you are designing an airbag system for a new model of automobile. In this example, a minor mistake in timing (causing the airbag to deploy too early or too late) could be catastrophic and cause harm. Thus, a hard real-time system is required; you need assurance as the system designer that no individual cognitive process will exceed certain timing constraints. On the other hand, if you were to design a mobile phone that received streaming video, it may be ok to lose a modest total of data occasionally even though on average it is important to hold up with the video stream. For this application, a soft real-time operating system may serve.
The main detail is that, if programmed right, an RTOS can guarantee that a program will melt down with very consistent timing. Real-time operating systems do this by providing programmers with a high level of command over how tasks are prioritized, and typically also allow checking to get sure that important deadlines are taken on.
In contrast to real-time operating systems, the most popular operating systems for personal computer utilization (such as Windows) are called general-purpose operating systems. While more in-depth technical data on how real-time operating systems differ from general-purpose operating systems is fed in a section below, it is important to recall that there are advantages and disadvantages to both types of OS. Operating systems like Windows are designed to maintain user responsiveness with many programs and services running (ensuring "fairness"), while real-time operating systems are planned to move critical applications reliably and with precise timing (paying attention to the programmer's priorities).

Important Terminology and Concepts
Determinism: An application (or critical piece of an application) that runs on a hard real-time operating system is referred to as deterministic if its timing can be guaranteed within a certain margin of error.
Soft vs Hard Real-Time: An OS that can absolutely guarantee a maximum time for the operations it performs is referred to as hard real-time. In contrast, an OS that can usually perform operations in a certain time is referred to as soft real-time.
Jitter: The amount of error in the timing of a task over subsequent iterations of a program or loop is referred to as jitter. Real-time operating systems are optimized to provide a low amount of jitter when programmed correctly; a task will take very close to the same amount of time to execute each time it is run.
2. Example Real-Time Applications
Real-time operating systems were projected for two general classes of applications: event response and closed-loop control. Event response applications, such as automated visual inspection of assembly line parts, require a response to a stimulus in a certain quantity of time. In this visual inspection system, for example, each piece must be photographed and studied before the assembly line goes.
By careful programming an application that works on a hard real-time operating system, designers working on event response applications can ensure that a reaction will happen deterministically (within a certain maximum amount of time). Looking at the parts inspection example, using a general-purpose OS could result in a part not been inspected in time - thus delaying the assembly line, pulling the party to be discarded, or sending a potentially defective part.
In contrast, closed-loop control systems, such as an automotive cruise control system, continuous process feedback data to adjust one or more productions. Because each output value depends on treating the input data in a specified amount of time, it is critical that loop deadlines are satisfied in order to ensure that the right outputs are created. What would take place if a sail control system failed to define what the throttle setting should be at a given peak in time? Once once more, hardened real-time operating systems can ensure that control system input data is treated in a reproducible amount of time (with a fixed worst-case maximum).
It should also be noted that many applications that must run for extended periods of time can benefit from the reliability that an RTOS can provide. Because real-time operating systems typically run a minimum band of software rather than many applications and processes at the same time, they are easily suited for systems that require 24-7 operation or where down-time is impossible or expensive.

3. Below the Hood: How Real-Time OSs Differ from General-Purpose OSs
Operating systems such as Microsoft Windows and Mac OS can provide an excellent platform for training and running your non-critical measurement and control applications. Even so, these operating systems are planned for different use cases than real-time operating systems, and are not the ideal platform for racing applications that need exact timing or extended up-fourth dimension. This segment will identify some of the major under-the-hood differences between both types of functioning systems, and explain what you can expect when programming a real-time application. 
Setting Priorities
When programming an application, most operating systems (of whatever type) allow the coder to set a precedence for the overall application and even for different tasks within the application (threads). These priorities serve as a signal to the OS, dictating which operations the designer feels are most significant. The finish is that if two or more tasks are ready to play at the same time, the OS will function the task with the highest precedence.
In practice, general-purpose operating systems do not invariably follow these programmed priorities strictly. Because general-purpose operating systems are optimized to run a mixture of applications and processes simultaneously, they typically turn to make certain that all tasks receive at least some processing time. As a consequence, low-priority tasks may in some cases have their priority boosted above other higher priority projects. This ensures some amount of run-time for each task, simply implies that the designer's wishes are not invariably observed.
In contrast, real-time operating systems fall out the programmer's priorities much more rigorously. On most real-time operating systems, if a high priority task is using 100% of the processor, no other lower priority projects will be given until the higher priority task finishes. Hence, real-time system designers must program their applications carefully with priorities in mind. In a typical real-time application, a designer will place time-critical code (e.g. Event response or a control code) in one section with a real high precedence. Other, less-important code such as logging to disk or network communication may be united with a section with a lower precedence.
Interrupt Latency
Interrupt response time is measured as the measure of time between when a device generates an interrupt and when that device is serviced. While general-purpose operating systems may contain a varying quantity of time to react to a given interrupt, real-time operating systems must assure that all interrupts will be serviced within a certain maximum amount of time. In other words, the interrupt latency of real-time operating systems must be restrained. 
Performance
One common misconception is that real-time operating systems deliver better functioning than other general-purpose operating systems. While real-time operating systems may offer more honest operation in some instances due to less multitasking between applications and services, this is not a pattern. Actual application performance will depend on CPU speed, storage architecture, program characteristics, and more. 
Though real-time operating systems may or may not increase the speed of execution, they can offer a lot more accurate and predictable timing characteristics than general-purpose operating systems.


for more tutorials please goto here.......