Francis's Blog

I end up playing with a lot of technology. My blog includes ruminations on various topics, and are hopefully helpful or otherwise of interest.

Incredible Lightning, Deafening Thunder

posted Aug 4, 2012, 7:59 PM by Francis Esmonde-White

This evening (August 4th 2012) we had a thunderstorm in Ann Arbor. Just as the storm started, we experienced the loudest thunder we have ever heard. I have previously been in buildings during a lightning strike (about 20 feet from the strike), and the thunder tonight was far louder. Three or four super-loud thunderclaps happened between 9:30 and 10 pm, with a delay of between 3 and 10 seconds from the lightning to the arrival of the thunder (so it wasn't even near us). Karen and I could feel the percussive force from each thunderclap in our chests.

A quick web search suggested that many other people have recently experienced similar extreme lightning & thunder... Extreme lightning with super-loud thunder? What's going on?


Better Network Diagnostic Tools

posted Feb 26, 2012, 9:42 AM by Francis Esmonde-White

Today I ran across these network diagnostic tools. These are far more specific than the tools I have previously used, and can also be used to detect network throttling. These tools have been developed by a consortium of academic and industrial partners.

http://www.measurementlab.net/measurement-lab-tools


Privacy & Training, Good Free Options

posted Feb 25, 2012, 10:03 AM by Francis Esmonde-White   [ updated Feb 26, 2012, 6:34 PM ]

Recently I have been going through various trainings for working with human subjects. It's amazing to learn about the strong infrastructure and guidance provided in order to maximize the safety and quality of research done with human subjects.

One of the big issues in work with human subjects is guaranteeing privacy and confidentiality of subjects. I don't foresee collecting any personally identifiable information about study participants, but the trainings have led me to think carefully about how to properly store and work with data.

There are a couple of great options available for encryption of data and communications. These are pretty sparsely used, but the tools have substantially advanced in both quality and user-friendliness since I last looked into what's available (over about the past 5 years).

The first tool is TrueCrypt. It is a software that can be used to create a virtual hard drive on a computer. It can also create a virtual hard drive inside what looks like empty space in a virtual hard drive. All the truly empty space is also filled with random numbers. Both virtual hard drives are encrypted (cannot be read without knowing a very special key), and without encrypting them it's impossible to know whether or not there are actually even any volumes or files inside. For example, if a laptop which holds the study data was lost, it would be very difficult to access the data without knowing the encryption key. This seems to hold a lot of potential for safely storing human subjects data. Unfortunately, it doesn't seem to be certified according to Federal Information Processing Standard (FIPS 140-2), which means it probably isn't sufficient for safeguarding patient data.

The second tool is GPG. GPG is one technology developed to encrypt emails. Did you know that all you email gets transmitted across the internet as plain-text? It's like having your all your letters mailed as post-cards (no envelopes), and instead of the postal service handling them, they get passed from person-to-person until they reach their destination. Using a system like GPG, the message can be encrypted (put into an envelope) so that it would be very difficult for anyone but the desired recipient to read the contents. There are two keys: One is a private key, which is required to open a message. The other is a public key, which can be used to encrypt a message, but not to open it afterwards.

However, there are a lot of challenges in using GPG, the greatest one being both the sender and recipient need to use GPG in order to actually use the system. Otherwise GPG is like having the only fax machine in the world. A second major problem is that most web-based email doesn't natively support GPG encryption. There are plugins for various browsers that support both encryption and decryption of email (Chrome, Firefox) in web services like GMail. However, there are still big limitations, like the subject line being plain-text. A third challenge is that the sender and recipient also need to exchange encryption-keys before they can read their messages. This is either done by directly exchanging the public-keys (by email for example), or by having the public keys available on a publicly accessible "keyserver". Note that only the public key should be shared... a private key that gets shared defeats the whole purpose of encryption.

New modem, different speed

posted Jul 17, 2011, 8:46 AM by Francis Esmonde-White   [ updated Jul 17, 2011, 9:11 AM ]

The Speedstream 4100B DSL modem that I was previously using died (was overheating and rebooting). AT&T sent us a new modem, this one is a Westell F90-6100 modem, for which it's a little less clear on how to set up bridge mode. I ended up finding the instructions on the AT&T web site for how to set up bridge mode, and configured it for use with my NETGEAR N600 (WNDR3700). When I first set it up, it worked fine for about 5 minutes. Then the internet connection dropped out (the internet light on the DSL modem would go out).

Based on comments in the NETGEAR forums, I suspected that the MTU size was the issue. I used http://www.dslreports.com/tweaks to determine the optimal MTU packet size. The optimal packet size turned out to be 1470. I previously had the MTU set to 1500 (the max the WNDR3700 will support). I think that's where the issue arose. After setting the MTU to 1470, I haven't had any further problems.

With my new settings, the ping time is 35 ms, with a download speed of 1.32 Mbps, and an upload speed of 0.32 Mbps (using the flash-based tool located at http://www.speedtest.net/).

AT&T vs Comcast Home DSL Speed Test

posted Jan 6, 2011, 8:35 PM by Francis Esmonde-White   [ updated Mar 10, 2011, 12:07 PM ]

Since tonight I can't seem to sleep, I thought why not test out my DSL connection speed. At home we have two internet connections, one through AT&T, the other through Comcast. Have you ever tested your broadband speed?

I'm posting results from 3 online bandwidth testing sites. I run each test twice and recorded the second value in the table below.

Test 1: The first is a flash-based tool located at http://www.pcpitstop.com/internet/bw.asp, it's really easy to use and fairly simple graphics, and has 4 server options. I was testing against the server in Washington DC.
Test 2: The second is another flash-based tool located at http://www.speedtest.net/, it's much more elaborate graphics, and has a lot of different server options. This was testing against a server in Southfield, MI.
Test 3: The third test is another flash-based tool, located at http://www.dslreports.com/speedtest?flash=1. I trusted DSLreports.com more than other sites, as I have read articles there before. It has 6 server options. I chose Chicago, IL for my first test. The interface shows an analog meter, but the flash applet doesn't run very smoothly (I can see it freeze up and the results get skewed as soon as it does). The results are pretty far off from what the other tests have reported. That is to a sprint server, so at first I thought that might be the issue, but it gives equally skewed results with Washinton DC or Toronto. Note that they're also selling/referring broadband plans. Undue bias? This one gives the error "Warning: ISP upload compression was detected. Your upload speeds may be inaccurate." I'm not even bothering to use it the second time around.
Test 4: The fourth test is http://testmy.net/. They're trying hard to get me to run extra tests on my computer to explain why the results are so slow. The exact text was: "I see that you're on a Windows PC. Test PC Speed after your internet test to discover hidden issues with your computer." Bias perhaps? 
Test 5: The fifth test is http://reviews.cnet.com/internet-speed-test/. Somehow, I get much better results with the CNET test, again closer to the first two results. Too bad there are no upload or ping results.

I'm testing two connections: our home AT&T connection (lowest cost possible), and CrossTown Wireless (running through Comcast), which we get for free through our apartment complex. It's definitely worth mentioning that I get a 5-bar signal strength on a 802.11n WPA-PSK network connection for my home AT&T, while the CrossTown Wireless is through a 2-3 bar 802.11g unsecured connection. It's definitely not a fair comparison.

Upload Speed
(Mbps)
Test 1Test 2Test 3Test 4Test 5
AT&T0.320.280.3000.312N/A
Comcast1.020.95 N/A 0.425N/A

Download Speed (Mbps)Test 1Test 2Test 3Test 4Test 5
AT&T1.201.240.5250.5901.236
Comcast2.001.82 N/A 1.0301.499

 Ping Latency
(ms)
 Test 1Test 2Test 3Test 4Test 5
AT&T666660N/AN/A
Comcast4945N/AN/AN/A

Well, the test results seem pretty clear, particularly in light of me using a far worse wireless signal with the Comcast tests. Now I have to explain to myself why we pay for AT&T service (we like having our own connection). On the positive side, my paid internet is apparently supposed to be even slower (for downloading). Perhaps our situation would be different if our neighbors were sucking up tons of bandwidth watching TV shows or downloading torrents on the apartment complex connection. At the very least, I think I'll start watching TV online through our free Comcast connection.

Kindle vs iPod Touch: Reading Journal Articles

posted Dec 28, 2010, 8:46 AM by Francis Esmonde-White   [ updated Mar 10, 2011, 12:07 PM ]

Karen and I read a lot of journal articles. I mostly read them on my laptop (a 13" MacBook Pro), sometimes printing them out if I need to make annotations. A few months ago, I found the Discover application for our iPod Touch tablets. Since then, I have started to read pdf articles on my iPod. This Christmas we received a Kindle as a present, so now we have another way to read articles. In this post, I will outline some of the differences, and dispel the misconceptions that I previously held. First, here are how the 3 devices I read on look together in my dining room with one of my journal articles pulled up.


The most obvious differences are in the relative size and brightness of each screen. Clearly my laptop and iPod have much brighter screens than the Kindle, which doesn't have a backlight. The Kindle reflects the ambient light only, so it can't be used in the dark (but it can be used in bright sunlight). I find it more comfortable reading on the Kindle than the backlit devices, because the extremely bright backgrounds cause eye strain for me. All have a neutral color balance, but the background of the Kindle screen is not as bright as a piece of white paper. It's a bit more like phone-book paper than novel paper, with a grey tint.

The laptop screen size easily allows me to read both columns of text on one screen. But everyone knows how articles look on a laptop screen.

The Kindle screen size is midway between that of the laptop and iPod. Putting the Kindle in landscape mode (by pressing the "Aa" key while reading an article and changing the Screen Rotation) allows two columns of text to be read one one screen at a modest but readable size. The main journal text looks like an 8-9 point printed font size (a bit on the small side). The figure captions are readable but uncomfortably small, even for my young eyes. It is possible to zoom on the text (again using the "Aa" button, and selecting between "fit-to-width", "150%", "200%", "300%", and "actual size"). Once zoomed in, the 5-way button (the Kindle equivalent of arrow keys) allow fine-grained movement of the view-screen. Figures look great, but I don't know how a color figure would look.


The iPod screen is definitely too small to read both columns in a single view, even in landscape mode. However, the ease of zooming and the great controls mean that it's really simple to get one column  to occupy the screen. Likewise, figures can be zoomed into and even color figures look great. One difficulty is with large figures, where you can either zoom in, or see the whole figure, but it's definitely a compromise.

A big disadvantage of the Kindle is the setup of controls used to adjust the screen. It's uncomfortable and they have reinvented terms that we're all used to. They rename the use of WiFi and 3G networks to download content as "wispernet". The limited keyboard is very irritating, particularly in the first 5 minutes of using the device. To register the account you need the "@" key, which requires opening the symbol menu (pressing the "Sym" button) and scrolling to the @ symbol. Likewise for entering other punctuation like dashes. Numbers can be accessed using the symbol menu, but also via holding the "Alt" key and pressing "q" through "p" for the numbers 1-9 and 0. Why not use alt-"." to access a dash? It seems arbitrary selected and poorly worked out. It would be very helpful to have the alternate character values printed directly on the Kindle. And why not expand the Alt-key accessible characters while at it? The screen also sometimes displays ghost images, but it can be manually refreshed to clean up the image by pressing Alt-"G" (an extremely convenient function). Finally, when browsing PDF files, the end of each page is visible on it's own screen. As shown below, this is really goofy, and reminiscent of the early days of the Adobe reader. Hopefully this will be fixed in software updates.


Getting articles onto the Kindle is definitely easy. Just drag and drop PDF's from your computer into the Kindle "documents" folder with the standard USB A to mini-B cable connected. Unfortunately, the Kindle doesn't charge while connected to my laptop. It is also possible to email PDF's to your Kindle, but this seems tedious and inconvenient to me. With my iPod, I can charge the iPod by connecting the proprietary Apple iPod cable to the laptop USB port. But I can't easily drag and drop PDF's through the standard file system options. By connecting the iPod and laptop to a wireless network, I can quickly and easily transfer PDF's to the iPod through any browser on my laptop. The iPod interface has one major advantage: the Discover application allows you to easily sort PDF files into folders and sub-folders. Since I have hundreds of articles on many different topics, this is tremendously helpful. With the Kindle, I have to scroll through 27 screens of items, with seven items per page. It is possible to make "collections", but it isn't possible to make "collections" within other "collections". This is another example of the goofy renaming of common terms like file folders.

Overall, the Kindle is a lot more comfortable to read on, definitely displays journal articles quite nicely, and is a lot less expensive than the iPod. The interface is less convenient than the iPod. The additional features of the iPod (email, calendar, contacts, maps, games, ect) also make it extremely convenient around the house.

Here are some other comparisons of the Kinde with the iPod/iPad:

Unlocking the AT&T LG GS390 Prime GoPhone (for free)

posted Dec 27, 2010, 4:04 PM by Francis Esmonde-White   [ updated Mar 10, 2011, 12:08 PM ]

I have been looking around the web for a few weeks now trying to figure out how to unlock my AT&T LG Prime phone. I often travel to Canada, but the AT&T GoPhone prepaid service doesn't work in Canada. Since I already have a nice cell phone, I wanted to unlock the phone for use with Canadian prepaid networks.

Searching Google for "unlock LG prime phone" is like dropping into an abyss of nearly identical commercial services. I started shopping around, and found a bunch of places that offer cell phone unlock codes (I think the cheapest I found was around 10$). I didn't really want to spend any money on the unlock codes, but my local Radio Shack wasn't able to unlock the phone for me.

Today I went into a local AT&T wireless store, and asked them about it. It turns out to be extremely simple: I called 611, spoke to an AT&T customer service representative, and she gave me the unlock code. It was fast, and the representative was really helpful.
  1. The first step was getting the IMEI number, by dialing *#06# on the keypad, which immediately displays the IMEI number.
  2. I read the IMEI number to the service representative, who (after 2 minutes) then gave me the unlock code.
  3. I wrote the unlock code down (being careful not to make any mistakes: if you enter the wrong number 10 times the phone will lock up completely).
  4. Next, turn off the phone and remove the AT&T GoPhone SIM card out of the phone. Put in a SIM card from another cellular network (such as one from a friend's phone who doesn't use AT&T GoPhone service), when you turn on the phone it will boot up and display a message about the phone being restricted ("Invalid SIM. Network Lock"). Select the 'unlock' button at the bottom of the screen.
  5. Enter the unlock code that the AT&T representative gave you, then enter it again.
  6. The phone will display "Your phone is unlocked"
  7. Turn off and put your original GoPhone SIM back into the phone.
  8. Turn the phone on. It will now be back on the AT&T network, but also unlocked from the AT&T network, so you can use the phone with other networks.
I have included a video below of someone else unlocking their phone. Remember: you can get the unlock code for free from AT&T, you don't need to buy it online.

Also: Some people on YouTube don't seem to realize that the code shown in the video will not work for their phone. The code is different for every phone, you will need to call AT&T for your own phone!

Edit: Lots of people seem to be looking for the following sentence: ' "invalid sim network lock" lg prime.' This is an error message that appears when you put a non-AT&T SIM card into the LG prime. It just means that the phone is rejecting the SIM card because the phone is locked to the AT&T network. If you want to use the phone with another network, just call AT&T and ask them for the unlock code.

LG Prime Unlock Video



Syncing Contacts into an LG GS390 Phone

posted Dec 26, 2010, 9:21 PM by Francis Esmonde-White   [ updated Apr 25, 2011, 9:49 AM ]

I recently picked up a new phone, the LG GS390 (or LG Prime). I use it with my AT&T GoPhone plan, which is less expensive than other options since I don’t use the phone much. It has a touchscreen interface, and a bunch of nice features like a small still/video camera, sound recorded, timers, FM radio and so on. I used to use a Samsung SGH-A137 phone, but it had terrible call quality.

Unfortunately, I couldn’t find any information about how to transfer my existing contacts onto the phone. The LG and AT&T web sites both neglect to describe how to import your contacts into the phone. I have a lot of contacts in my gmail account, and I definitely didn’t want to copy them all over one-by-one using the phone interface. After spending some time searching the web, I didn’t find anything relevant on copying contacts to the phone. But- I did figure it out.

You don't need a special cable, or any other hardware or software tools to do this- and it’s free. You also don’t need to unlock your phone.

I haven’t found any documentation on this process, but it works really well (or at least it did for me, with about 900 contacts). It turns out that all you need to do is export your contacts to the Apple .vcf format (you can export to .vcf from gmail and several other email clients), and then that contacts file can be imported directly to the GS390. This is definitely an easy way to sync your contacts to the LG Prime, I don’t know why it’s not listed in the manual or on the LG web site.

Here’s what I did:
  1. From Gmail contacts select “export”, then for ‘Who do you want to export?’, select ‘Everyone (All Contacts)’. Under ‘Which export format?’, select ‘vCard format (for importing into Apple Address Book or other application)’. When you click the ‘export’ button, it will save a file ‘contacts.vcf’ onto your computer. Google's description of this process is pretty clear, so if you need more information, you should read the google help page. Google help also has a list of how to export your contacts from other email clients.
  2. Copy the contacts.vcf file from your computer onto the microSD card that you use with your phone (you should definitely get a microSD card if you don’t have one- they can be also be used to store photos, videos, and music on your phone). I bought an 8GB SDHC card for my phone, and it works well.
  3. Plug the microSD card into your phone, and open the ‘My Stuff’ folder in the phone menu, then select the ‘Memory Card’. This will allow you to see what files are on the microSD card. If anyone is interested, email me and I will post photos of the phone menus (since they're hard to describe).
  4. You should see ‘contacts.vfc’ listed towards the bottom of the file list. If you click on it, the screen will display “contacts.vcf. This is contacts backup file. Please choose restore to see the contacts.” There should also be a button labelled “restore” at the bottom of the screen.
  5. When you click the restore button, the phone will read all the contacts from the backup file and copy them into the contacts manager.
Voila, you’re done.


Using the iPod Touch to read scientific PDF's

posted Dec 26, 2010, 8:59 PM by Francis Esmonde-White   [ updated Mar 10, 2011, 12:08 PM ]

Karen and I have been using our iPod touch devices for several years. We love them (me perhaps slightly more), and use them for checking email, looking up recipes, looking at maps, and playing music through Pandora while we're at home. They're also pretty resilient, our older one still works properly despite me putting a long crack down the center of the screen while camping in Death Valley last summer.

A few months ago I found a really nice iPod application called Discover. It should also work for the iPhone and iPad. I am using the free version which is ad-supported.

Basically, when you run the app it will connect through any wireless network you have previously set up in the iPod Settings menu. When the app starts up, it creates a server on the iPod which you can upload files to and download files from. It makes a really cool file-transfer devices, but an even cooler scientific PDF reader. At first I was worried that it would be annoying to upload files through my web browser, but you can select many files at once (even whole directories), and they're all uploaded at the same time. The upload speed is also much faster than if it were going through the internet because the transfer happens on your local wireless network. For me it takes less than a minute to transfer 30 papers to the iPod.

Once you have uploaded the papers to the iPod, you browse to the papers from inside the Discover App, and read them by double clicking on the file. The PDF reader uses the same multi-touch as other iPod applications, using pinching to zoom, and pulling to scroll. Because the screen is a full color display with a fast refresh rate, it is like looking through a small window onto a printed journal page. However, because of the zoom feature, it is actually more convenient for looking at color figures than reading a PDF on a computer screen. I think that the iPod is better for color figures than the Kindle, though there are relatively few journal articles with color figures. It also handles the transition between individual pages really well, since it simply concatenates the beginning of each new page to the end of each old page, so there is no big whitespace gap between pages. It also automatically rotates the screen to switch between landscape and portrait view mode (this benefit is actually a big disadvantage when I browse things while lying in bed, because it forces me to hold the iPod at uncomfortable and odd angles). Finally, if you double-tap on a column of text, the screen automatically zooms into that column to effectively use the small screen.

Some final notes: the shiny touch-screen on the iPod is ALWAYS smudged with fingerprints, whereas the Kindle screen is always clean (albeit dust). The iPod screen makes my eyes hurt in the dark, and after a long day of staring at computer monitors, while the Kindle is always the same brightness as the surrounding environment, and much less tiring on my eyes (but also requires a reading-light since there is no backlight). 


On eBook Readers

posted Dec 26, 2010, 8:07 PM by Francis Esmonde-White   [ updated Mar 10, 2011, 12:08 PM ]

For the last two years I have been eyeing various e-book readers. The Kindle (Amazon), Nook (Barnes & Noble), Reader (Sony), Story (iriver), and the iPod touch (Apple) are the main ones I had been looking into. I read about several of them online, and I remember people discussing how the early ebook readers didn't handle scientific journal articles very well. That negative feedback has made me wary of the paperless devices- and none of the academics that I have chatted with about the subject have had anything positive to say about the ebook readers. Of course whenever Karen and I visit any bookstore, I still get drawn towards the displays with the ebook readers out of curiosity. Unfortunately, at every single store (without fail - and this includes at least 15 visits to various brick & mortar locations) I get the same disappointing response to my primary question at each store. "How well does your ebook reader handle scientific PDFs?" That's my primary concern, since Karen and I read a lot of journal articles. We often have to read & reference articles while writing papers, and it's really important that we be able to read the graphs, tables, and images in the manuscripts. Unfortunately, no store ebook reader display has any demos with scientific PDF's. (Considering the number of freely available scientific articles, also called open-access, it's shocking that no company selling ebook readers has decided to include a sample of articles as demos.)

Well this Christmas, Karen and I were given an absolutely lovely gift: a 6" kindle with WiFi. It turns out that the Kindle does a fine job of scientific journal articles (at least in my very limited test). I regret not getting one earlier.

The assortment of freely available classic literature books is staggering. I have known about Project Gutenburg for several years, but I didn't realize that they now books directly downloadable in kindle (and other) formats. Also, directly using WiFi on the Kindle, I have downloaded a ton of books right through the Amazon online store (completely freely). The free books are almost all out of copyright, meaning that for the most part only older titles are free. Yesterday I downloaded about 130 books while looking through the store. Feedback for the Amazon folks: It's extremely inconvenient that the Kindle doesn't have the ability to search by more than one criteria (including price range and genre). When it comes to reading books, I think that hands-down, I'll read literature on the Kindle. I'm not sold on periodicals (newspapers or magazines) or reference books (I particularly like the O'Reilly programming books), but I am now considering purchasing reference texts in ebook format rather than paper.

The device itself is extremely lightweight, and very comfortable to read on. I'm not sure that I like the keyboard and page-turning buttons yet, but they're definitely growing on me. I rarely need to read product manuals in order to get a good grasp on device menus, but I needed to read the Kindle manual to get a grasp on several aspects (like the device capacity, how to change the text size, and how the different power modes work).

Tonight I tried out one of my scientific PDF's with the Kindle (it's one of my articles, that will be published in the journal Applied Spectroscopy in January 2010). It worked extremely well. I just plugged the Kindle into my computer by USB, uploaded the PDF to the 'documents' folder, then was able to open the PDF file directly. It's a bit cumbersome scrolling through the pages, and the final few lines of each page end up occupying an entire scroll-screen to themselves. However, the text and figures both came out extremely well. I have no issues with the quality of the final output. The zooming and scrolling is definitely tedious, but using the shift-scroll key combo, it's manageable. I think that I may also use the Kindle for scientific PDF's.

Perhaps I will try to convince Karen that we should also get a 9.7" Kindle, but that's probably a bit premature, since we have had ours for less than 48 hours.

I will post some reference photos in another posting, comparing photos of the Kindle, iPod touch, and my MacBook Pro displaying the same PDF file.


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