vendredi 2 juillet 2010

Veille technologique semaine 26

Pour le bulletin de la semaine 26, je vous propose les articles suivants :
  • Etes vous multi-taches ? On connaît le multi-tâches pour les machines mais qu'en est-il pour les humains ? Des études montrent que au delà de trois tâches, l'efficacité humaine s'effondre. A prendre en compte dans vos activités.
  • Gmail de Google bientôt en HTML 5.
  • Les nouvelles fonctionnalité de l'OS Android 2.2 réalisé par Google, avec bientôt une version sur processeur x86 d'Intel (porté par Intel).
  • Les NIO 2 et le JDK 7 : l'accès aux attributs des fichiers.
  • La différence entre l'identité et l'égalité : exemple en C#
  • Les expressions lambda pour le JDK 7 : étude des différent cas.

Bonne lecture.

Multitasking Gets You There Later
Modern business relies on multitasking to get work done. Employees are evaluated on their ability to multitask. IT professionals are routinely assigned to multiple projects. Did we always do this? Does multitasking work? What are the real impacts of multitasking? Is there an alternative?

Costs of Multitasking
A person who works on more than one project incurs a cost at each shift from one project to the other. The primary cost is the time required to change context. We know that simple interruptions like a phone call can cost as much as 15 minutes of recovery time. The more complex the task, the more time it takes to make the shift.

If you are working on more than two projects the cost can be even greater. It may have been a long time since you worked on that project, taking more effort to remember where you left off. Alternately, if you shift frequently, your context-switching time is a larger proportion of your work time.

There are studies that show people are pretty good at shifting between two contexts for small tasks. In a short time scale this appears to have to do with our two brain hemispheres. To a certain extent, we can parallel process two independent tasks. For larger switches, we should expect some switching cost. Jerry Weinberg showed the escalating context switching costs accrued if each task has a 10% penalty, in reality the costs are frequently higher.

Google Gmail to harness HTML5
Google announced that it would be rendering many upcoming features for Gmail in HTML5.  Dragging and dropping files from the desktop into the browser will be just one new feature in Gmail's new standards-based update.  Google will also leverage HTML5's database standards (migrating away from the now-dead Google Gears storage; in favor of HTML5 Web Workers).

Cool Off This Summer with Fully Native x86 Froyo  
A senior VP at Intel has recently
stated that a fully native x86 version of Android 2.2 will be released this Summer.  All of the code will be sent back to the open branch being created for x86.  This could mean more Atom-powered Android tablets.

Introducing NIO.2 (JSR 203) Part 3: File System Attributes and Permissions support in NIO.2
In two previous entries I covered Introducing NIO.2 (JSR 203) Part 1: What are new features? and Introducing NIO.2 (JSR 203) Part 2: The Basics [2] In this entry I will discuss Attributes introduced in NIO.2. Using attributes we can read platform specific attributes of an element in the file system. For example to hide a file system

Comparing Values for Equality in .NET: Identity and Equivalence
The various ways of comparing two values for equality in .NET can be very
confusing. In fact if we have two objects a and b in C# there are at least
four ways to compare their identity, plus one operator that looks like an
identity comparison to add to the confusion:
1. if (a.Equals(b)) {}
2. if (object.Equals(a, b)) {}
3. if (object.ReferenceEquals(a, b) {}
4. if (a == b) {}
5. if (a is b) {}

As if that isn't confusing enough, these methods and operators behave
differently depending on:
whether a and b are reference types or value types
whether they are reference types which are made to behave like
value types for these purposes (System.String is one of these)

This article is an attempt to clarify why we have all these versions of equality, and what they all mean.

Lambdas in Java: An In-Depth Analysis
With the acquisition of Sun Microsystems out of the way, Oracle can get down to the serious business of revitalising what many have come to see as a stagnant language. High on many people's requirements is the ability to be able to pass functions around that are independent of classes, so that functions can be used as arguments to other function or method calls. Functional languages like Haskell and F# exist purely using this paradigm, and functional programming goes back eight decades to the Lambda Calculus, leading to the term Lambda being used in many languages to describe anonymous functions.

Aucun commentaire: