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2013 August

August 27, 2013

The Basics of Chrome OS

Choosing a computer can be a tall order. Obviously, you want a device that can do everything you need it to, but there are frequently other parameters that are worth consideration. Is it compatible with old files and documents? Where can it be used and how portable is it? How much will it cost? There have traditionally been three options: Macs, Windows PCs, and Linux PCs. But a young contender in the market is shaking things up.

Chrome OS, designed by Google, is a different breed of OS. It is almost exclusively a web browser, so it definitely lacks some serious functionality. But while it may fall short in application selection, Chrome OS makes up for it in speed, ease of use, and most importantly, price. The most popular Chromebook can be bought for $250.

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August 8, 2013

UO Blogs service a popular tool

Any faculty, staff or student on the UO campus has the ability to create a website, thanks to the relatively new UO Blogs service.

UO Blogs is a  centrally managed, WordPress-based content management system. It can be used by anyone with an active DuckID to create any kind of website or blog, from one used by a campus department to one used for projects or events.

The site takes users through the simple steps to create a website. Because WordPress is designed for low-tech users, the process isn’t complicated.

UO Blogs also allows for guest accounts for those who are not affiliated with the UO, making it “a great place to collaborate with colleagues off campus,” says Information Services Technology Service Desk Coordinator Kelsey Davis.

Launched in June 2012, the service has “really taken off,” Davis says.

The site has had more than 500,000 visitors since its inception. Currently, there are 3,522 sites and 3,763 users.

“We have sites ranging from student personal sites, to sites used by faculty for classes, to departmental/ administrative sites, to project sites and more,” Davis says.

She encourages faculty, staff and students to familiarize themselves with the service by checking out some of the examples of ways it can be used. Some links include http://alerts.uoregon.edu/, and http://blogs.uoregon.edu/artandhumanvalues/.

Visit the UO Blogs website for more information or to get started.

– from the UO Office of Strategic Communications

Source: Around the O.

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August 6, 2013

Xerox scanners/photocopiers randomly alter numbers in scanned documents

In this article I present in which way scanners / copiers of the Xerox WorkCentre Line randomly alter written numbers in pages that are scanned. This is not an OCR problem (as we switched off OCR on purpose), it is a lot worse – patches of the pixel data are randomly replaced in a very subtle and dangerous way: The scanned images look correct at first glance, even though numbers may actually be incorrect. Without a fuss, this may cause scenarios like:

  1. Incorrect invoices
  2. Construction plans with incorrect numbers (as will be shown later in the article) even though they look right
  3. Other incorrect construction plans, for example for bridges (danger of life may be the result!)
  4. Incorrect metering of medicine, even worse, I think.

To make things even more worse: The copiers in question are the common Xerox WorkCentres, and Xerox seemed to be unaware of the issue until we found out about it last Wednesday. Whats more, not only one different WorkCentre model seems to be affected, as we tested at least two with this issue (Xerox WorkCentre 7535 and 7556). Additionally, the current software release, as installed by xerox support, did not solve the issue, thus, the issue existed on the very old release we had installed, as well as on a very new one. The error has been confirmed by a xerox rental firm in the meantime, and Xerox is investigating as well, so it does not seem to be some dumb handling error or something similar (if I was thinking this, I of course would not publish it here).

As a result, anyone using those WorkCentres has to ask himself:

  • How many incorrect documents (even though they look correct!) did I produce during the last years by scanning with xerox machines? Did I even give them to others?
  • What dangers are imposed by such possible document errors? Is there a danger of life for someone?
  • Can I be sued for such errors?

Even though Xerox seems eager to solve the issue, because of the possible dangers an immediate publication of the issue is advisable. This is what I want to do with this article.

The rest of the article is organized as follows.

  • By showing some real world examples I outline how we got aware of the issue, and how subtle it is. As it is hard to believe that scan copiers randomly alter written numbers, picture evidence is provided. (At first, I thought someone makes fun of my with this error, too).
  • After that, I give some technical detail and describe the scan parameters set.
  • Also, there will be a short manual how to reproduce this error.

Read the rest of article at D. Kriesel.

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August 5, 2013

After Shibboleth is Installed

This post is for people who are setting up shibboleth service providers on their web servers.

Configuration

Look at https://it.uoregon.edu/idm/services/shibboleth-application-integration for common configuration procedure.

  • shibboleth2.xml: This file is where your shibboleth settings will reside. The default shibboleth site settings goes under ApplicationDefaults. Additional vhosts are managed with ApplicationOverride.
  • attribute-map.xml: This file defines the attributes used by the service provider. Add the attributes that you need to that file. Common attributes requested are user information like username (duckid), email address and directory information that all come from LDAP.

Testing Shibboleth

  • Once installed and configured go to your default shibboleth site URL: https://www.example.org/Shibboleth.sso/Login (The /Login depends on your shibboleth configuration). You can optionally set a target variable to redirect to after authentication. E.g. https://pcs.uoregon.edu/Shibboleth.sso/Login?target=https://pcs.uoregon.edu/
  • If you see a 404 error you probably have a redirect setup to send Shibboleth.sso (or any handlerURL you have setup) to some page on your website. Common problem with WordPress. Add RewriteCond %{REQUEST_URI} !^/?Shibboleth.sso/ to stop the redirect. In Shibboleth 2.5.2 you have to setup the redirect for any website that uses redirects otherwise you will see 404 errors.
  • Once you hit enter on that URL you should be redirected to your IDP to authenticate. Once authenticated if you see no errors you will be redirected to your site. Otherwise you will see errors.
  • Commons errors. Here are some possible ones that you should check for:
    • IDP is not configured for your Shibboleth address.
    • IDP is configured for https but you tried to connect with http. This includes using http in the target variable. Since we require https for Shibboleth it is recommended to make all traffic redirect to https.
    • Your server’s date is skewed. Make sure to use NTP and have it running and synced with ntp.uoregon.edu or any other reliable NTP server.
    • Check Shibboleth logs for errors as well.
  • Once authenticated go to https://www.example.org/Shibboleth.sso/Session to review your session and see if all the attributes you requested are being provided. If your attribute-map.xml is configured correctly you should see attributes you have access to.

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Nerd news: Dalai Lama video streaming tech specs

Dalai Lama at Matt Knight Arena

His Holiness the 14th Dalai Lama spoke to 11,000 guests at Matthew Knight Arena on Friday, May 10th, but thanks to a live video stream of his talk, his message reached at least twice that number.

Total views of the Dalai Lama video stream peaked at around 15,000, reaching a maximum of 4,339 simultaneous viewers. A total of 4.48TB of video and audio were delivered through the event.

While most viewed the event with a web browser on a desktop or laptop computer, 16.1 percent used a mobile device to watch the speech. (See views by device, below.)

The video and audio stream was carried via UOnet and the university’s new Vyvx service to the Content Delivery Network (CDN) provider, Level(3). There, the stream was transcoded sent back to campus. To handle the potential loads, Information Services used Puppet, a configuration managment system, to clone the two web servers that usually handle web traffic to www.uoregon.edu, adding 20 additional virtual machines to that pool of web servers.

Staff estimate that 75 percent of the video stream viewers were off-campus. Breakdown of the types of video streams corroborates the popularity of broadband connections, with 82 percent of customers viewing the video at 1.5Mbps or higher. (See video by bandwidth, below.)

The University of Oregon caps its 10Gbps inbound bandwidth at 1Gbps. The broadcast of the Dalai Lama pushed bandwidth usage beyond that limit, and Information Services staff temporarily removed the cap to allow for seamless streaming on campus. (See Network Traffic, below.)

The video and audio streams of the Dalai Lama’s visit were produced through a collaborative project led by UO Libraries’ CMET group and supported by UO Information Services, UO Strategic Communications, UO General Counsel’s office, UO Purchasing & Contracting, Network for Education and Research in Oregon (NERO), UO Marketing and Brand Management, Graystone Media, Level(3) Communications, and LabGency.

See statistics at IT connections.