ICALT is a annual international conference on Advanced Learning Technologies and Technology-enhanced Learning organized by IEEE Computer Society and IEEE Technical Committee on Learning Technology.
Paper Submission December 30, 2011
Theme of the 2012 edition (July 4-6, 2012) is:
with design inspired learning, fostering creativity and fun, complex educational experiences and their monitoring, ubiquitous learning and flexible environments
Windows Phone Now Supports Full PhoneGap Framework Features
“Microsoft today announced a good news for developers, the PhoneGap open source mobile framework support for Windows Phone is now complete. Windows Phone supports all the features PhoneGap currently offers as you can see in the image above. PhoneGap is a open source mobile framework that enables developers to build applications targeting multiple platforms, by using standard web technologies (HTML5, CSS and JavaScript).
http://feedproxy.google.com/~r/WmPowerUser/~3/YykMozbKvbM/
“I was just complaining in your new forums that Windows Phone 7 need more access to peripherals so we could also have cool toys such as controlling quadro-copters with our phones.
It seems the folks from Uniquemethod.hu have read my mind, as they have created this cool demo of a real life teeter game controlled by both an Android and Windows Phone, using their own proprietary UMCS protocol, made possible by sockets access in Windows Phone Mango.
The demo is being performed over WIFI, but hopefully rumours of updated Bluetooth protocols are also true in future versions of Windows Phone, so we can take part in more of the fun.”
-Sent from Weave for Windows Phone 7
NoSQL’s great, but bring your A game
http://feedproxy.google.com/~r/OmMalik/~3/NvOp6dcMMEs/
“MongoDB might be a popular choice in NoSQL databases, but it’s not perfect — at least out of the box. At last week’s MongoSV conference in Santa Clara, Calif., a number of users, including from Disney, Foursquare and Wordnik, shared their experiences with the product. The common theme: NoSQL is necessary for a lot of use cases, but it’s not for companies afraid of hard work.
If you’re in the cloud, avoid the disk
According to Wordnik technical co-founder and vice president of engineering Tony Tam, unless you’re willing to spend beaucoup dollars on buying and operating physical infrastructure, cloud computing is probably necessary to match the scalability of NoSQL databases.
As he explained, Wordnik actually launched on Amazon Web Services and used MySQL, but the database hit a wall at around a billion records, he said. So, Wordnik switched to MongoDB, which solved the scaling problem but caused its own disk I/O problems that resulted in a major performance slowdown. So, Wordnik ported everything back onto some big physical servers, which drastically improved performance.
And then came the scalability problem again, only this time it was in terms of infrastructure. So, it was back to the cloud. But this time, Wordnik got smart and tuned the application to account for the strengths and weaknesses of MongoDB (“Your app should be smarter than your database,” he says), and MongoDB to account for the strengths and weaknesses of the cloud.
Among his observations was that in the cloud, virtual disks have virtual performance, “meaning it’s not really there.” Luckily, he said, you can design to take advantage of virtual RAM. It will fill up fast if you let it, though, and there’s trouble brewing if requests start hitting the disk. “If you hit indexes on disk,” he warned, “mute your pager.”
Foursquare’s Cooper Bethea echoed much of Tam’s sentiment, noting that “for us, paging the disk is really bad.” Because Foursquare works its servers so hard, he said, high latency and error counts start occurring as soon as the disk is invoked. Foursquare does use disk in the form of Amazon Elastic Block Storage, but it’s only for backup.
EBS also brings along issues of its own. At least once a day, Bethea said, queued reads and writes to EBS start backing up excessively, and the only solution is to “kill it with fire.” What that means changes depending on the problem, but it generally means stopping the MongoDB process and rebuilding the affected replica set from scratch.
Monitor everything
Curt Stevens of the Disney Interactive Media Group explained how his team monitors the large MongoDB deployment that underpins Disney’s online games. MongoDB actually has its own tool called the Mongo Monitoring System that Stevens said he swears by, but it isn’t always enough. It shows traffic and performance patterns over time, which is helpful, but only the starting point.
Once a problem is discovered, “it’s like CSI on your data” to figure out what the underlying problem is. Sometimes, an instance just needs to be sharded, he explained. Other times, the code could be buggy. One time, Stevens added, they found out a poor-performing app didn’t have database issues at all, but was actually split across two data centers that were experiencing WAN issues.
Oh, and just monitoring everything isn’t enough when you’re talking about a large-scale system, Stevens said. You have to have alerts in place to tell you when something’s wrong, and you have to monitor the monitors. If MMS or any other monitoring tools go down, you might think everything is just fine while the kids trying to have a magical Disney experience online are paying the price.
By the numbers
If you’re wondering what kind of performance and scalability requirements forced these companies to MongoDB, and then to customize it so heavily, here are some statistics:
Foursquare: 15 million users; 8 production MongoDB clusters; 8 shards of user data; 12 shards of check-in data; ~250 updates per second on user database, with maximum output of 46 MBps; ~80 check-ins per second on check-in database, with maximum output of 45 MBps; up to 2,500 HTTP queries per second.
Wordnik: Tens of billions of documents with more always being added; more than 20 million REST API calls per day; mapping layer supports 35,000 records per second.
Disney: More than 1,400 MongoDB instances (although “your eyes start watering after 30,” Stevens said); adding new instances every day, via a custom-built self-service portal, to test, stage and host new games.
For more-technical details about their trials and tribulations with MongoDB, all three presentations are available online, along with the rest of the conference’s talks.
Feature image courtesy of Tony Tam, Wordnik.
Related research and analysis from GigaOM Pro:Subscriber content. Sign up for a free trial.Putting Big Data to Work: Opportunities for EnterprisesMigrating media applications to the private cloud: best practices for businessesInfrastructure Q3: OpenStack and flash step into the spotlight”
-Sent from Weave for Windows Phone 7
Windows Phone Device Manager Version v1.8 public beta now available [Homebrew]
http://feedproxy.google.com/~r/wmexperts/~3/B3y9zyC40hM/story01.htm
“For those looking to literally explore more of your developer-unlocked Windows Phone (including CheveronWP7 Labs), you’ll want to grab v1.8 of the Windows Phone Device Manger by Schaps. The app is a one-stop place for doing all sorts of cool things on your phone via your Windows Desktop–it’s basically the old Device Manager from Windows Mobile but augmented with many news functions. Here are just a few:
Applications management: view, install/uninstall & update applications File management: explore device, exchange files with your phone Sync files, folders and favorites with phone Send to Windows Phone (to send files, apps, ringtones, web links in one click) Detailed device information (CPU, ROM, RAM, storage, network, battery, OS,…) Detailed storage information Add and manage custom ringtones Send SMS, E-mail, notes directly from PC (without needing cloud services) Remote screen view and take screenshots of the phone Backup/restore files and application data Create and manage backup/restore of the phone Full access to apps isolated storage….
And there’s much more. Anyways, the latest version is now available to the public and seems to be working on most 2nd generation phones, including the HTC TItan and Samsung Focus S. The app is technically free but a donation (if you use it) is highly recommended for continued development of this project.
Source: TouchXperience; WPDM v1.8; via WPCentral Forum (dragonide)”
-Sent from Weave for Windows Phone 7
AdDuplex creating list of Windows Phone Sites
http://feedproxy.google.com/~r/WmPowerUser/~3/-IUx8Iz6Ky0/
“For developers, getting the word of their app out is essential if they do not wish to be drowned out by a deluge of ebooks and other marketplace spam.
One of the best ways of promoting apps are letting the Windows Phone blogs know about them, and to make things a bit easier for developers AdDuplex have created a site which compiles a list of Windows Phone websites, both big and small, and whether for example they do reviews or not.
Impressively the database already has more than 50 entries, which is both a sign of the hard work of the team there and also how productive the Windows Phone community has been in getting the word out about our favourite mobile OS.
The site, WindowsPhoneSites.com can be seen here, and if your favourite site is not there, its addition can also be requested.
Read more about the effort at AdDuplex here.”
-Sent from Weave for Windows Phone 7
Microsoft Kinect used to map asteroids, glaciers, other scary things
http://www.engadget.com/2011/12/15/microsoft-kinect-used-to-map-asteroids-glaciers-other-scary-th/
“Ken Mankoff is a PhD student at the University of California, Santa Cruz, where he studies ice and ocean interactions. He also counts himself among a growing legion of environmental scientists who have begun using Microsoft’s Kinect to create detailed, 3D maps of caves, glaciers and even asteroids. As Wired reports, the Kinect has garnered something of a cult following within the scientific community, especially among those who, until now, have relied upon comparatively more expensive and complicated technologies to gather detailed 3D data. The approach du jour for most researchers is something known as Light Detection and Ranging (LIDAR) — a laser-based technology capable of creating precise maps over relatively large areas. The Kinect, by contrast, can only see up to 16 feet in front of itself, but at just $120, it’s significantly cheaper than the average LIDAR system, which can run for anywhere between $10,000 and $200,000. It’s also surprisingly accurate, capable of capturing up to 9 million data points per second.
Mankoff, for one, has already used the device to map a small cavern underneath a glacier in Norway, while Marco Tedesco, a hydrologist at the City College of New York, is looking to attach a Kinect to a remote-controlled helicopter, in the hopes of measuring so-called meltwater lakes found on glaciers during the summer. Then there’s Naor Movshovitz, also a PhD student at UC Santa Cruz, who’s more interested in using the Kinect and its image processing software to figure out how asteroids behave when broken up by a projectile. There are limitations, of course, since the device still has trouble performing amidst severe environmental conditions, though its supporters seem confident they’ll find a solution. Read more at the source link below.
Microsoft Kinect used to map asteroids, glaciers, other scary things originally appeared on Engadget on Thu, 15 Dec 2011 16:05:00 EST. Please see our terms for use of feeds.Permalink | Email this | Comments”
-Sent from Weave for Windows Phone 7
Ra Puke Moana 